Leonardo Da Vinci: a Complete Biography

Introduction

Leonardo da Vinci stands as one of the most extraordinary human beings who has ever lived. To call him simply a painter does a profound injustice to the astonishing breadth of his mind. To call him a scientist alone fails to capture the exquisite beauty of his art. To describe him as an inventor ignores the depth of his philosophical thinking. He was all of these things simultaneously, and in being all of them at once he became something that transcends any single category of achievement. His name has become synonymous with genius, with curiosity, with the restless and insatiable appetite for knowledge that defines the greatest human minds.

Born in the small Tuscan hill town of Vinci in the middle of the fifteenth century, Leonardo grew up in a world on the cusp of profound transformation. The Italian Renaissance was remaking European culture from the ground up, rediscovering the wisdom of ancient Greece and Rome while simultaneously pushing beyond it into new territories of art, philosophy, and natural inquiry. Leonardo did not merely participate in this renaissance; in many respects he personified and accelerated it, dragging whole fields of investigation forward by sheer force of his intellect and his imagination.

What makes Leonardo so compelling across the centuries is not merely that he was exceptionally good at many different things, though he was extraordinary at virtually everything he attempted. What sets him apart from other polymaths and other geniuses is the particular manner in which he integrated his various pursuits into a single unified project of understanding. He did not paint as one separate activity and study anatomy as another and design machines as a third and investigate geology as a fourth. For Leonardo, all of these activities were expressions of the same deep desire to comprehend how the world worked, how light fell upon curved surfaces, how muscles moved bones, how water flowed around obstacles, how birds navigated the invisible currents of the wind. Art and science were not separate endeavors for him but different aspects of a single comprehensive investigation into the nature of reality.

His paintings are among the most celebrated in the world. The Mona Lisa and The Last Supper have achieved a kind of cultural saturation that makes it genuinely difficult to see them freshly, to experience the shock of radical originality that must have struck viewers who encountered them for the first time. Yet even beneath the accumulated weight of their fame, even beneath centuries of reproduction, parody, and commentary, these works retain a power that repays the closest attention. They demonstrate a mastery of light and shadow, a subtlety of psychological portraiture, a command of composition and pictorial space that remained unsurpassed for generations after Leonardo's death and that still hold their own against everything that has been produced in the centuries since.

His notebooks are equally extraordinary, and in some ways more so, since they were not known to the wider world for centuries after he filled them with his characteristic mirror-writing and packed them with drawings, diagrams, calculations, and observations. Thousands of pages survive, and they contain anticipations of many of the central discoveries of modern science and engineering. He envisioned flying machines, armored vehicles, solar concentrators, hydraulic machinery, and anatomically accurate representations of the human body at a time when most of these ideas were virtually unthinkable to his contemporaries. He studied the movement of water with the same intensity he brought to the study of human expression. He dissected human corpses to understand how the body actually functioned rather than simply accepting what ancient authorities had written about it centuries before.

His life spanned more than six decades of extraordinary intellectual and artistic productivity, though it was not without its frustrations, disappointments, and projects left magnificently incomplete. He abandoned a great many works before they were finished, either because his restless mind was perpetually moving to the next question before the current one was resolved, or because the projects themselves proved technically or logistically impossible given the materials and resources of his era. He was, by all accounts, a compelling and charismatic personality, tall in his youth and handsome throughout his life, gifted in conversation, accomplished as a musician, possessed of a personal magnetism that drew patrons, students, rivals, and admirers throughout his long career.

Understanding Leonardo fully requires understanding the world he inhabited. The Florence of his youth was a city undergoing a cultural revolution sponsored by wealthy merchant families, above all the Medici, who understood that the patronage of art and learning was itself an expression of power and a claim to civilizational prestige. The Milan he moved to in his middle years was dominated by the Sforza dynasty, ambitious rulers who needed artists to beautify their court and engineers to strengthen their military position and manage their territory. The Rome and France of his later years were caught up in the turbulences of the Italian Wars, great conflicts that reshuffled the political map of Europe and left Leonardo navigating the competing demands and rapidly shifting fortunes of powerful patrons whose own security was never guaranteed.

This biography attempts to do justice to the full dimensions of Leonardo's life and work, tracing his development from his early years in the Tuscan countryside through his long career in the service of various Italian and eventually French patrons, exploring his artistic achievements and scientific investigations in careful detail, and assessing his enduring legacy in painting, science, engineering, and the broader culture of the modern world. It is a story of one of the most remarkable minds the human species has ever produced, a mind that in many ways belonged not to the fifteenth and sixteenth centuries in which it lived but to a future that was still centuries distant and that we ourselves have only partially caught up with.

Early Life in Vinci

The town of Vinci sits on the southern slopes of Monte Albano in the Tuscan hill country situated between the city of Florence and the Ligurian Sea. It is a modest place, surrounded by the olive groves and vineyards that formed the agricultural backbone of Tuscan life during the Renaissance period. The land is gently beautiful in the way of much of central Italy, with rolling hills punctuated by dark cypress trees, shallow valleys carved by small streams, and the ever-present smell of wild herbs and earth that characterizes the Tuscan countryside in every season. It was here, in the mid-fifteenth century, that Leonardo was born to a Florentine notary named Ser Piero da Vinci and a young woman of humble origins named Caterina.

The circumstances of his birth were irregular but by no means unusual for the era. Ser Piero was a prosperous and ambitious man from a family of notaries who had served the community of Vinci and its surrounding district for several generations. The notarial profession placed the da Vinci family securely within the respectable middle class of Tuscan society, neither aristocratic nor common, but connected to the legal and administrative fabric that held the society together. Ser Piero had not yet married when Leonardo was born, and Caterina was a woman of humble origins, most likely the daughter of a local farmer or perhaps an indentured laborer on one of the local estates. Their liaison produced a child, but it did not produce a marriage. Ser Piero soon arranged a match with a woman from a family more appropriate to his social standing, while Caterina eventually married a local man and established a separate household in which she raised other children.

The young Leonardo was taken into his father's household rather than remaining with his mother, and he was raised in the comfortable environment of the da Vinci family home by his paternal grandparents, Antonio and Lucia, and particularly by his uncle Francesco, who would prove to be an important figure in his early development. This arrangement, while it must have created certain emotional complications for the boy, gave him a stable and materially comfortable early childhood within a prosperous rural family with connections to the professional and civic life of the region. Ser Piero acknowledged his illegitimate son and brought him up, though Leonardo's status as a bastard would follow him throughout his life in certain practical and legal ways, most significantly barring him from inheriting his father's profession, since the notarial guild of Florence required legitimate birth for membership.

The landscape of the Vinci region left a permanent and deep mark on Leonardo's imagination, his aesthetic sensibility, and ultimately his scientific thinking. The hills and rivers of Tuscany, the play of morning light through olive leaves, the movement of streams over smooth pebbles, the flight of hawks above the vineyards, the way mist gathered in the valleys at evening and dissolved in the morning sun: all of these sensory experiences fed the extraordinary visual memory and acute perceptual sensitivity that would underpin his artistic and scientific work throughout his entire life. Many scholars who have studied his paintings and drawings carefully have noted the distinctive landscapes visible in the backgrounds of his works and suggested that these misty, rocky, water-carved vistas are transformed memories of the Tuscan countryside he explored with such intensity and pleasure as a child.

His uncle Francesco was apparently particularly significant in Leonardo's early development. Unlike Ser Piero, who was a busy professional with an active legal practice in Florence, Francesco was essentially a gentleman farmer who spent his days on the family estate, and he seems to have given his young nephew considerable freedom to wander the surrounding countryside, observe natural phenomena, and indulge the curiosity about the natural world that would become the defining characteristic of Leonardo's intellectual life. Later in life Leonardo would write with great passion about the importance of direct observation in understanding nature, insisting that those who merely read what others had written about natural phenomena would always know less than those who actually looked at the world for themselves. These childhood rambles through the Tuscan hills, watching the behavior of insects and birds, examining the structures of rocks and the growth patterns of plants, studying the way small streams cut channels through soft earth and deposited sediment in wider pools, were the very beginning of a lifetime practice of extraordinarily attentive looking.

His formal education was limited by the standards of the Florentine humanist elite of his era, though it was probably adequate by the standards of the rural community in which he grew up. He learned to read and write in Italian and acquired a working knowledge of basic arithmetic sufficient for the practical calculations of everyday life. What he did not receive, and what would remain a source of genuine intellectual frustration throughout his adult life, was a thorough classical education in Latin and Greek, the foundational languages of serious scholarly discourse in the Renaissance world. This gap in his formal preparation placed him at a disadvantage in certain contexts, since the accumulated knowledge of antiquity and of the medieval scholarly tradition was encoded primarily in Latin texts to which he had only limited access. He compensated by acquiring Latin to some degree as an adult and by seeking out people who could translate relevant passages for him, but he never achieved the facility with the classical languages that marked a truly learned man of his era.

Yet this same limitation was in some respects a liberation. Because Leonardo could not simply open a Latin text and defer to what an ancient authority had written about anatomy or optics or hydraulics, he was driven back toward the world itself, toward direct observation and practical experiment as his primary modes of investigation. While his contemporaries debated the finer points of ancient texts, Leonardo was watching water flow around stones, dissecting animals to understand their internal organization, and measuring the proportions of human bodies with calipers. This fundamentally empirical orientation, shaped in part by the accident of his imperfect education, became one of the most distinctive and productive features of his intellectual character.

His artistic gifts were apparent from an early age. He possessed the acute visual sensitivity and the remarkable manual dexterity that would eventually make him one of the supreme draughtsmen in the history of art. It is not entirely clear precisely when or through what specific incident his exceptional abilities became visible to his family, but at some point it became evident to those around him that this boy had unusual gifts that deserved cultivation and a proper outlet. The path that was open to a talented young man with extraordinary visual abilities but without the social standing or legitimate birth required for the learned professions was apprenticeship in the workshop of an established master craftsman, and Ser Piero, who had professional contacts throughout the Florentine world, made arrangements to secure his son a place in one of the finest workshops the city had to offer.

The Florence that Leonardo entered as an adolescent was one of the most remarkable cities in Europe, a commercial and financial metropolis that had also become the epicenter of the extraordinary cultural transformation we now call the Renaissance. The Medici family, whose wealth was founded on international banking and trade, had made the cultivation of art and learning into a deliberate and highly sophisticated instrument of political prestige. Under the successive patronage of Cosimo de Medici, his son Piero, and above all his grandson Lorenzo, known to history as Lorenzo the Magnificent, Florence became a center of artistic production, philosophical inquiry, literary achievement, and architectural innovation that had no equal anywhere in the European world. Painters, sculptors, architects, philosophers, classical scholars, and musicians were drawn to the city from across the Italian peninsula and beyond, and the workshops of the city's leading artists were constantly busy with commissions from the church, from the wealthy merchant families, and from the Medici themselves.

It was into this extraordinarily stimulating environment that the young Leonardo arrived from his small hill town, and the city would shape him profoundly and permanently. The Florence of the later fifteenth century was not merely a place where beautiful things were produced; it was a place where ideas about art and beauty and the relationship between artistic practice and the investigation of nature were being actively debated and constantly reformulated. Artists were not simply craftsmen executing prescribed programs according to established conventions; they were thinkers engaged in working out a new understanding of the visible world and of humanity's relationship to it. Leonardo arrived at precisely the right moment to absorb these ferments at their most productive and to carry them further than any of his contemporaries could imagine or achieve.

Apprenticeship With Verrocchio

When Ser Piero da Vinci sought a master to receive and train his gifted son, he had either the good judgment or the fortunate connections to secure a place in the workshop of Andrea del Verrocchio, one of the finest artistic establishments in all of Florence. Verrocchio was a remarkably versatile and technically accomplished artist who worked with equal facility in painting, sculpture, goldsmithing, and other crafts, and whose workshop handled commissions of virtually every kind from the most powerful and discriminating patrons in the city. He was closely connected to the Medici court and was trusted with some of the most significant and public artistic projects in Florence. For a young artist of exceptional promise and ambition, there could hardly have been a more stimulating or better-connected environment for professional development.

The workshop system of Renaissance Florence was the primary institution through which artistic training and professional identity were transmitted from one generation to the next. A young apprentice entered the studio of an established master typically during his early adolescence and spent a period of years learning the craft from the ground up in a thoroughly practical and graduated way. He would begin with the most elementary and humble tasks, grinding pigments, preparing wooden panels and canvas supports, cleaning tools, running errands for the master and his clients, and he would gradually be entrusted with more demanding and more technically complex work as his skills developed and his master's confidence in him grew. He would spend long hours studying and copying the works his master had already produced, learning by imitation the particular visual habits and technical preferences of the workshop tradition he was entering. He would assist in the execution of new commissions, painting drapery or background landscapes or architectural elements while the master reserved the most demanding and prestigious passages for himself. Eventually, if he was talented and assiduous, he would begin to contribute work of sufficient quality that it could appear without distinction from the master's own hand in finished works going out to clients under the workshop's name.

Leonardo entered Verrocchio's workshop as a teenager and remained there for approximately six years, eventually achieving the rank of independent master and registering with the guild of Florentine painters that gave him the legal right to accept commissions under his own name. During these formative years he absorbed a technical training of the very highest quality. Verrocchio was particularly skilled in the rendering of surface textures, in the handling of complex drapery, in the depiction of the human figure in difficult and demanding poses, and in the integration of figures into architectural and landscape settings that maintained spatial coherence and visual harmony. He was also a thoughtful and theoretically aware practitioner who was interested in the science of painting, in the optical properties of pigments and glazes, in the mathematics of perspective, and in the anatomical accuracy of the figures he sculpted and painted.

Leonardo absorbed all of this systematic technical knowledge and went far beyond it in directions that were entirely his own. His natural perceptual gifts, combined with the rigorous training he received in Verrocchio's workshop, produced a draughtsman and painter of ability that had no precedent in his era. His surviving drawings from this period already demonstrate a confidence, a sureness, and a subtlety of observation that belie his youth. He could capture the precise structure of a particular face or the specific fall of light on a fold of drapery with a certainty of line and an economy of means that distinguished his work immediately from that of any of his contemporaries in the workshop or in the city at large.

One of the most revealing and frequently cited stories about Leonardo's early development involves a large painting attributed to Verrocchio's workshop depicting the Baptism of Christ. According to an account first published by the artist and biographer Giorgio Vasari in his celebrated collection of artists' lives, Verrocchio asked his young apprentice to paint one of the angels in the left foreground of the composition, and when Verrocchio examined what Leonardo had produced, he was so utterly overwhelmed by its quality and by the evidence of talent it displayed that he resolved never to paint again, recognizing that the student had not merely equaled but surpassed the master. While the specific details of this story are undoubtedly embellished in the retelling, careful examination of the painting in question does reveal a passage of work that is unmistakably more subtle, more nuanced, and more technically accomplished than the surrounding areas. The angel's luminous, softly modeled face, the delicate atmospheric quality of the landscape glimpsed behind the left edge of the composition, the gentle dissolution of hard contours into ambient shadow: all of these are generally accepted by scholars to be by Leonardo rather than by Verrocchio, and they are qualitatively different from anything else in the picture.

Whether or not Verrocchio literally swore off painting after seeing his apprentice's contribution, the story captures something genuinely true about the nature of Leonardo's talent and its relationship to his training. He was not simply a diligent and capable student who had mastered the techniques he had been taught and was now executing them with professional competence. He was a revolutionary talent who was already developing approaches to painting, to the rendering of light and atmosphere and psychological character, that went beyond anything his master or his master's distinguished contemporaries had achieved. The specific technique he was already beginning to develop, which involves the deliberate softening of contours and the gradual dissolution of sharp edges into tonal gradations, anticipates what would later be called sfumato and represents a fundamental reorientation of how painting could relate to the reality of visual experience.

The workshop environment of Verrocchio's studio exposed Leonardo to an extraordinarily wide range of intellectual and artistic contacts and ideas. Verrocchio's shop was a gathering place for some of the most important minds in Florence, and the city itself was home to philosophers, mathematicians, architects, natural philosophers, and classical scholars whose ideas circulated freely in the informal but highly productive networks of patronage, friendship, and intellectual exchange that connected the cultural life of the city. Leonardo encountered in this environment the mathematical theories of perspective that were being developed simultaneously by practicing artists and by theoretical mathematicians. He was exposed to the anatomical investigations that a small number of progressive artists and physicians were beginning to conduct, examining actual human bodies in order to understand the structures they were attempting to depict with accuracy. He was immersed in the broader current of humanist thinking that placed the study of the natural world and the recovery of ancient knowledge at the center of educated intellectual life.

He developed during these Florentine years the habits of visual attention and systematic record-keeping that would eventually produce his extraordinary notebooks. He carried a small drawing book with him wherever he went, even when walking through the streets of the city, and he used it constantly to sketch things that caught his attention or aroused his curiosity: the characteristic expression of a face encountered in a crowd, the specific way light fell through leaves in the morning, the posture of a man carrying a heavy load, the configuration of clouds on a summer afternoon, the branching pattern of a tree against the sky. These quick studies were not merely preparation for specific paintings or workshop projects; they were an expression of his fundamental and compulsive drive to understand the visible world by subjecting it to the most intense and sustained observation of which he was capable.

His period in Verrocchio's workshop concluded when he had achieved the status and confidence necessary to seek independent commissions, and before he left Florence entirely for the opportunities that awaited him in Milan, he had already produced several independent works of considerable significance and ambition. An Annunciation painted during this period demonstrates his already mastery of the representation of light, of the rendering of botanical detail, of the construction of convincing perspective space, and of the characterization of figures through subtly observed gesture and expression. An unfinished altarpiece known as the Adoration of the Magi, commissioned for the monastery of San Donato a Scopeto but never completed, reveals even more dramatically the extraordinary ambition of his artistic thinking and the innovations he was already developing in composition, in the representation of crowds and psychological interaction, and in his approach to the relationship between the devotional content of religious imagery and the realistic observation of human behavior. The Adoration in particular shows a mind utterly unwilling to accept conventional solutions, a mind that was pushing against the established boundaries of what a religious painting could do and mean.

The years with Verrocchio were, in every sense, the foundation upon which the entire subsequent edifice of Leonardo's career was built. They gave him technical mastery of the highest order, professional connections and reputation in the most important artistic city in Europe, intellectual stimulation and contact with the most advanced thinking of his era, and above all the confidence to seek out the kind of ambitious and generous patronage that would allow him to pursue the vast range of investigations and projects that his exceptional mind was already conceiving. When he left Florence for Milan, he carried with him not just the skills of a master painter but the beginnings of a comprehensive program of investigation into the natural world that would occupy the remaining decades of his life.

Milan and the Sforza Court

The decision to leave Florence and seek a position at the court of Milan was one of the most consequential of Leonardo's entire career, and it shaped the direction of his life and work in ways that would have been difficult to predict when he made it. Florence was unquestionably the cultural capital of Italy and in many respects of the entire European world, but it was also a city in which Leonardo had not yet achieved the level of consistent recognition and stable, generous patronage that his ambitions required. The Medici, while appreciating talented artists and maintaining a court atmosphere hospitable to intellectual and artistic achievement, had not focused their patronage specifically and sustainably on Leonardo in ways that gave him the security and resources he needed to pursue his most ambitious projects. He had unfinished commissions, unrealized promises, and a growing sense that the Florentine environment, for all its extraordinary richness and stimulation, was not the ideal context for his particular and unusual combination of artistic, scientific, and engineering interests.

Milan offered something fundamentally different. Ludovico Sforza, known throughout Italy as il Moro on account of his dark complexion and his personal heraldic device, was the effective ruler of the Duchy of Milan, one of the most powerful and wealthy of the Italian states, and he was precisely the kind of ambitious, militaristic, image-conscious patron who needed and could reward what Leonardo had to offer. Ludovico wanted great artists to beautify his court and celebrate his magnificence, engineers to strengthen his fortifications and design his weapons and manage his territories, musicians and poets to entertain his court and compose in his honor, and general intellectual luminaries whose brilliance would reflect favorably on his rule and establish his court as a center of civilization comparable to the greatest courts of antiquity. Leonardo was all of these things and more, and he had the intelligence and the social acuity to understand exactly how to present himself most effectively to a potential patron of this kind.

The letter that Leonardo apparently sent to Ludovico to introduce himself and make his case for employment is one of the most fascinating documents in the entire history of relations between artists and their patrons. Rather than leading with his reputation and achievements as a painter, which was after all his most prestigious and widely recognized accomplishment, Leonardo led with a detailed enumeration of his capabilities as a military and civil engineer. He described with systematic precision his ability to design portable bridges capable of withstanding attack, to construct specially designed drainage channels and tunnels for siege operations, to build armored vehicles capable of advancing through enemy formations, to design cannons and mortars and other weapons of destruction, to construct ships suited to naval warfare, to divert rivers away from the water sources of besieged cities, and to design and execute works of civil engineering of every kind. He also offered his abilities as a sculptor, capable of producing the great equestrian monument that Ludovico had long been contemplating as a memorial to his father, the dynasty's founder. And he mentioned, almost as a brief afterthought at the very end of his letter, that he could also paint as well as anyone, should that be of interest to the duke.

The strategic intelligence displayed in this letter is remarkable. Leonardo understood precisely what a ruler like Ludovico valued most and what would distinguish him most usefully from the many other artists and craftsmen competing for ducal patronage. He led not with beauty but with power, not with art but with engineering, because he understood that in the context of the constant political and military tensions of the Italian states, the ability to fortify cities and design weapons was worth infinitely more to a ruler than the ability to paint beautiful altarpieces. The letter worked, and Leonardo secured a position at the Sforza court that would prove to be the longest and in many ways most productive of his career.

He remained in Milan for approximately seventeen years, far longer than any other period he spent in a single city, and during this extraordinarily productive time he executed some of his most important artistic works, developed many of his most far-reaching scientific and engineering investigations, enjoyed the kind of sustained patronage and relative financial security that was otherwise rare in his career, and established himself definitively as the greatest living artist and one of the most remarkable intellects in Europe.

Among the grandest and most consuming projects of his Milanese period was the commission to create a great equestrian statue of Francesco Sforza, Ludovico's father and the military genius who had founded the Sforza dynasty's dominion over Milan. This monument was to be cast in bronze and was designed from the beginning to be the largest equestrian statue created since the time of ancient Rome, a work that would establish Milan's cultural ambition and the Sforza family's claim to a place in the ranks of history's great dynasties. Leonardo threw himself into this project with characteristic thoroughness and systematic rigor. He studied horses obsessively over an extended period, making dozens upon dozens of drawings of horses in every conceivable pose and from every conceivable angle, studying their anatomy with the same comprehensive attention he was beginning to bring to human anatomy, understanding the structure of their muscles and bones, the specific proportions of their bodies, the characteristic ways they moved and stood and carried their weight. He investigated the technical problems of bronze casting at the scale he envisioned and developed innovative casting procedures intended to manage the unprecedented size of the work. He eventually created a full-size clay model of the horse, approximately eight meters in height without the rider, which was displayed publicly and received with enormous admiration from contemporaries who were able to see it.

In the end, however, the Sforza Horse was never cast in bronze, and the magnificent clay model was ultimately destroyed. The invasion of northern Italy by the French king Charles VIII interrupted the project and diverted the large quantities of bronze that had been accumulated for the casting to the more immediately urgent purpose of manufacturing cannons to resist the military threat. The clay model survived for some years but was eventually used as target practice by French soldiers after they captured Milan and expelled Ludovico Sforza. It was a devastating loss, and it established a pattern of frustrated ambition, meticulous preparation followed by an incomplete or destroyed result, that would recur with painful regularity throughout Leonardo's career.

The great mural painting of The Last Supper, executed on the wall of the refectory of the convent of Santa Maria delle Grazie in Milan, was a far more successful achievement, and it produced one of the most celebrated and influential paintings in the entire history of art. The commission came from Ludovico Sforza himself, and Leonardo worked on it for approximately three years, developing the composition with painstaking care before beginning to paint. The subject is the moment described in the Gospel of John when Christ, seated at supper with his apostles, announces that one of those present at the table will betray him. The dramatic possibilities of this subject were obvious, but no previous painter had exploited them with anything approaching the psychological intensity and compositional sophistication that Leonardo brought to bear.

His composition is organized around the seated figure of Christ at the exact center of the composition, isolated and framed by the open window behind him, forming a stable and serene triangular shape against which the turbulence of the surrounding apostles registers with maximum force. The twelve apostles are arranged in four groups of three figures on either side of Christ, and within each group the figures respond to Christ's announcement in individualized and clearly differentiated ways, clustering together in urgent conversation, recoiling in shock, reaching forward in emphatic denial, turning to their neighbors in bewildered questioning. Leonardo differentiated each apostle not merely by his physical type and coloring but by a specific psychological response that was entirely consistent with what the tradition said about his particular character and his relationship to Christ. The figure of Judas, rather than being isolated on the near side of the table as convention dictated, is here kept among the other apostles on the far side, distinguished primarily by his posture of guilty withdrawal and by the shadowed quality of his face.

The technical difficulties Leonardo created for himself with The Last Supper became apparent within his own lifetime and have plagued the work ever since. Rather than using the traditional fresco technique, in which paint is applied rapidly to fresh wet plaster and becomes permanently fused with the wall surface as it dries, Leonardo chose to work on a dry wall prepared with a special ground of pitch, gesso, and mastic, applying his paint over this ground in a manner that allowed him the extended working time and the capacity for revision and subtle adjustment that his working method required. Fresco demanded rapid, decisive execution, and the qualities that made Leonardo a great painter, his tendency to revise, to reconsider, to build up effects gradually through multiple layers of increasingly delicate adjustment, were fundamentally incompatible with the demands of the fresco technique. But the mixed medium he chose instead proved deeply unstable, and the paint began to flake and deteriorate within a generation of the work's completion. The painting we see today, much restored and partially repainted over the centuries, is a considerably diminished version of what Leonardo originally created, yet even so its power and its revolutionary character remain unmistakable to any attentive viewer.

Beyond the great artistic commissions, the Milan years were extraordinarily productive for Leonardo's scientific and technical investigations across an extraordinary range of domains. He designed hydraulic machines to regulate the elaborate canal system of the Lombard plain, one of the most sophisticated hydraulic infrastructure systems in Europe. He began the systematic anatomical investigations that would eventually produce his unparalleled series of anatomical drawings. He designed theatrical machinery and elaborate pageants for court entertainments, creating spectacular mechanical effects that reportedly astonished and delighted Ludovico's courtiers. He worked on his notebooks with increasing systematic ambition, organizing his observations into what he hoped would eventually become comprehensive treatises on painting, on anatomy, on hydraulics, on mechanics, and on other subjects. He designed military fortifications, canals, and urban planning schemes. He also served as a kind of general intellectual ornament to the court, participating in philosophical discussions, demonstrating scientific experiments, and performing the role of the universal genius that a Renaissance court of pretension required.

The Notebooks and Scientific Investigations

The notebooks of Leonardo da Vinci represent one of the most remarkable bodies of evidence for the workings of a single human mind that has ever existed. They consist of many thousands of pages, in various states of preservation and organization, covered with his characteristic right-to-left mirror script and packed with drawings, diagrams, numerical calculations, theoretical reflections, observational records, mechanical designs, and occasional personal remarks that give the reader an intimate and often startling sense of the mind that produced them. Leonardo wrote in mirror script, from right to left across the page, a practice that has been variously explained as a natural consequence of left-handedness that prevented him from smearing wet ink as he wrote, as a desire to keep his thoughts private from casual observation, or simply as an idiosyncratic habit that he developed early and maintained throughout his life. Whatever its origin, the mirror script gives the notebooks a quality of intimate privacy, as if the reader is being permitted to observe a mind thinking rather than being addressed as an audience.

The scope and diversity of subjects covered in the notebooks is truly staggering, extending far beyond anything that could be explained by the requirements of his professional work as an artist or engineer. In a typical sequence of pages one might encounter a detailed anatomical study of the shoulder joint with careful labels identifying each muscle and tendon, followed by a quick sketch of an interesting cloud formation observed from a window, followed by notes on the mathematical relationships between musical intervals, followed by a design for a novel kind of mechanical loom, followed by a reflection on the nature of memory, followed by a geometric proof attempted with varying success. The apparent disorder and the constant shifting of subject matter in the notebooks is not a sign of intellectual incoherence; it is rather a record of a mind so perpetually active and so voraciously curious that it could not confine itself to any single subject for long without noticing connections to other subjects and following those connections wherever they led.

His investigations into the nature and behavior of water were among the most sustained, the most systematic, and arguably the most profound of all his scientific pursuits. He returned to the subject of water throughout his entire life, and the notebooks contain hundreds and hundreds of pages devoted to the study of hydraulic phenomena. He watched flowing water with an intensity that bordered on obsession, spending long periods observing how streams and rivers moved, how water behaved when it encountered different kinds of obstacles, how it formed the characteristic vortex spirals and eddies that he found aesthetically as well as scientifically captivating. He studied waves on water surfaces, the formation of drops, the behavior of water as it fell over edges, the way it percolated through different types of soil, and the long-term effects of moving water on the rocky and earthen channels through which it flowed. He designed controlled experiments to test specific hypotheses about hydraulic behavior and developed what amounted to a comprehensive science of fluid dynamics several centuries before the formal mathematical treatment of the subject was developed by later scientists.

His geological investigations were in many respects his most philosophically radical contribution to human knowledge. By carefully observing the layered rock formations of the Alpine foothills and elsewhere in Italy, and by thinking carefully about how those layers could have been formed, he arrived at conclusions about the history of the earth that were far in advance of the received opinion of his era. He observed that marine fossils, the shells of mollusks and the bones of sea creatures, could be found embedded in mountain rock at high elevations far from any sea, and he rejected all of the conventional explanations offered by natural philosophers for this phenomenon. He rejected the idea that these were mere accidents of nature, stones that happened to resemble organic forms but had no genuine biological origin. He rejected the suggestion that they had been deposited by Noah's flood, since a flood of finite duration could not produce the multiple distinct layers of different fossil-bearing strata that he observed in actual rock formations. He concluded instead that these mountains had once been beneath the sea, that the organisms whose remains he was examining had lived and died in a marine environment, and that the transformation of the seafloor into mountain was the result of slow geological processes operating over periods of time immensely greater than the few thousand years implied by the scriptural account of creation. This was not a safe or comfortable conclusion in the intellectual environment of his era, and Leonardo was careful about how explicitly he expressed such views, but in his private notebooks he stated them with remarkable clarity and confidence.

His optical investigations went far beyond what any practical necessity of painting could have required. He understood that the eye was a lens system and that it operated by receiving light from external objects rather than by emitting rays toward those objects, which was still a matter of genuine debate among natural philosophers who continued to take seriously the ancient emission theories of vision. He made careful studies of the properties of lenses and mirrors, investigating the behavior of light at curved surfaces, and he designed controlled experiments to test his conclusions about refraction and reflection. He grasped intuitively that refraction, the bending of light rays as they pass from one transparent medium to another, was responsible for the apparent displacement of objects seen through water or glass, and he worked out the approximate geometric relationships governing this phenomenon. He studied the formation of shadows with great precision, distinguishing between the zone of complete shadow and the surrounding penumbra of partial shadow, and working out the geometric rules that govern their size and shape in relation to the size of the light source and the distance of the shadowed surface.

His mechanical investigations were grounded in what amounted to a genuinely systematic science of machines, a comprehensive analysis of the principles governing the behavior of all mechanical devices. He understood that all complex machines were combinations of a small number of simple machines, the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw, and he studied each of these in turn, working out the mathematical relationships between force, distance, and work that governed their behavior. He understood the concept of mechanical advantage, the way in which simple machines allow a smaller force applied over a larger distance to produce a larger force over a smaller distance, and he applied this understanding consistently and creatively in his mechanical designs. He also studied the problem of friction with unusual care, recognizing it as the primary source of energy loss in all mechanical systems and making systematic observations about how the amount of friction depended on the materials of the surfaces involved, the load pressing them together, and the speed of relative motion. His conclusions on friction anticipated the formal laws of friction developed by later scientists and engineers.

His work on the notebooks was motivated by the long-term ambition to transform his accumulated observations and insights into a series of comprehensive published treatises that would constitute a systematic encyclopedia of natural knowledge. He worked toward treatises on painting, on anatomy, on mechanics, on hydraulics, on the flight of birds, on geology, on optics, and on other subjects throughout his career. None of these treatises was ever completed to his satisfaction, and most of them were never published during his lifetime. The ambitious program of systematic publication that would have transmitted his knowledge to his contemporaries and successors remained perpetually unrealized, a casualty of the same restless, perpetually advancing curiosity that made his investigations so extraordinary. He was always discovering something new that needed to be incorporated into the work, always revising and expanding his understanding in ways that made the project of summarizing it seem premature.

Painting and Artistic Masterworks

Leonardo's reputation as a painter rests on a relatively small number of surviving works, since he was famously slow and deliberate in his working methods and left many commissions either unfinished or only partially completed. But the paintings he did bring to completion are among the greatest achievements in the history of Western art, and the influence he exerted on the subsequent development of European painting has been deep, pervasive, and enduring in ways that are still being explored by art historians.

His approach to painting was grounded in a fundamental philosophical conviction that true painting required the most comprehensive possible knowledge of nature and of the principles governing its appearances. A painter who did not understand anatomy could not depict the human figure accurately. A painter who did not understand optics could not render light and shadow convincingly. A painter who did not understand geology and botany could not paint convincing landscapes. A painter who did not understand the science of perspective could not construct pictorial space that would satisfy an informed eye. These convictions were not merely theoretical positions for Leonardo; they were the practical basis of his working method, and they drove the scientific investigations that occupied so much of his time and energy alongside his actual painting.

The technique he developed and refined throughout his career, which art historians have come to call sfumato, is perhaps his most distinctive and most influential contribution to the technical vocabulary of painting. The word derives from the Italian for smoke or haze, and it describes a method of painting in which the transitions between areas of light and shadow are blurred and dissolved rather than defined by crisp, clear contour lines. Where most painters of his era and before him defined the forms of their figures with confident outlines that separated them cleanly from their backgrounds and from each other, Leonardo deliberately softened these boundaries, allowing the edges of forms to dissolve into the surrounding atmosphere in a way that approximated much more closely the actual experience of seeing. He understood, through his optical investigations, that the eye does not perceive objects as having sharp edges in the way that drawn outlines suggest; objects are surrounded by air, and air has optical properties that blur and soften the perception of edges, particularly at a distance. By rendering this actual optical experience in paint, he achieved a quality of atmospheric reality and psychological ambiguity that was entirely new in painting.

The Virgin of the Rocks, which exists in two versions of somewhat different character and quality, one now in the Louvre in Paris and one in the National Gallery in London, is one of the most fully realized achievements of his mature painting. The composition brings together the Virgin Mary, the infant Christ, the infant John the Baptist, and a kneeling angel in a setting of extraordinary strangeness and beauty, a grotto of dark, water-carved rock pierced by openings that allow glimpses of a distant landscape suffused with a mysterious, filtered light. The figures are arranged in a triangular grouping that achieves remarkable stability and formal elegance while also expressing through gesture and glance a complex network of devotional and narrative relationships. The angel's face, particularly in the Louvre version, is among the most hauntingly beautiful things Leonardo ever painted, its softly luminous features emerging from deep shadow with a quality of supernatural presence that no description can adequately convey.

The Mona Lisa has become the most famous painting in the world, and its fame has become in some respects an obstacle to seeing it clearly, since it arrives in the viewer's experience so thoroughly encrusted with prior commentary, imitation, and parody that the actual painted object can be difficult to reach. Yet the painting repays the effort to see it fresh, because what it achieves is genuinely astonishing even now. The woman shown in the three-quarter pose, seated before a landscape that recedes into misty distance on either side of her, has an expression that refuses to resolve itself into any single definable emotional state. The corners of her mouth and eyes are rendered with sfumato so subtle and so carefully calibrated that the expression changes depending on how the viewer's gaze moves across the face, shifting between a suggestion of the beginning of a smile and a suggestion of something more distant and contemplative. This elusiveness is not a technical accident or an effect of the painting's deterioration over time; it is a deliberate and immensely sophisticated artistic strategy, a way of representing the mobility of inner life that no portrait painter before Leonardo had even attempted.

The landscape visible behind the figure is equally innovative and equally rewarding of close attention. The two halves of the landscape visible on either side of the sitter are depicted from slightly different vantage points, with the horizon on the right appearing somewhat higher than the horizon on the left, a subtle spatial discontinuity that creates a barely perceptible sense of unease in the viewing experience. The distant mountains, water, and mist are rendered with atmospheric perspective of extraordinary refinement, the distant forms becoming progressively bluer, hazier, and more indistinct in a way that creates a convincing sense of vast spatial recession. The landscape is not a topographically identifiable view of any actual place but a constructed imaginary world that carries its own internal coherence and its own peculiar emotional atmosphere.

His portrait of a young woman holding a small white ermine, known as the Lady with an Ermine and generally identified as a portrait of Cecilia Gallerani, the mistress of Ludovico Sforza, is one of the most psychologically penetrating portraits in the history of art. The sitter is shown in a moment of arrested movement, turning her head and shifting her attention as if responding to some stimulus arriving from outside the picture frame. The quality of alertness and intelligence in her expression, the sense of a specific personality captured in a specific and transient moment of attention, is unlike anything earlier portraiture had achieved. The ermine she holds, which in Renaissance iconography carried symbolic associations with purity and also with Ludovico's personal emblems, participates in the composition as an active presence, turning its head in a direction corresponding to and amplifying the sitter's own turn, creating a dynamic of mutual attention that animates the entire surface of the painting.

His religious paintings demonstrate the same extraordinary qualities of psychological characterization and technical refinement that distinguish his portraits. The Saint Anne with the Virgin and Child, in which three generations of the Holy Family are arranged in a compact pyramidal grouping with a landscape of spectacular Alpine character behind them, shows Leonardo at his most ambitious in the construction of multi-figure compositions in which every element is related to every other element by bonds of psychological connection and formal rhyme. The unfinished Saint Jerome in the Wilderness, though never brought to completion, reveals in its bold and sculptural treatment of the aging saint's body and its atmospheric rendering of the rocky landscape the extraordinary range of Leonardo's artistic imagination.

His last great painting, the Saint John the Baptist, is in some ways the strangest and most unsettling of his works. The figure of the Baptist, shown alone against a dark background without any of the usual attributes of the wilderness or of his role as precursor to Christ, points upward with one hand while a smile plays across his features that carries something of the same enigmatic quality as the Mona Lisa. The extreme contrast between the luminous figure emerging from impenetrable darkness, combined with the ambiguous expression and the gesture of pointing into an invisible beyond, creates an effect of mysterious presence that has fascinated and sometimes disturbed viewers for centuries.

Anatomy and the Human Body

Leonardo's investigations into the structure and workings of the human body constitute one of the most extraordinary episodes in the entire history of science, and they represent perhaps his most significant and most completely realized intellectual achievement outside the realm of painting. Working in conditions that were physically difficult and often socially precarious, he examined and dissected human corpses on a scale that was unprecedented for a non-physician in his era, producing in the process a body of anatomical drawings that were not equaled in accuracy, comprehensiveness, and clarity for more than a century after his death and that remain objects of wonder and admiration as works simultaneously of scientific investigation and of the highest artistic accomplishment.

His initial motivation for anatomical study was the same as that of several other progressive artists of his era: he believed that a painter who did not understand the internal structure of the human body could not depict its external appearance with true accuracy, because the surface forms of the living body are determined at every point by the bones and muscles beneath the skin. The contour of an arm, the shape of a torso, the position of a knee, the movement of a shoulder: all of these visible external forms are the products of specific internal structures, and a painter who rendered them from purely external observation alone would inevitably make errors that betrayed his ignorance of the underlying anatomy. This conviction, while it was shared by other thoughtful artists of his generation, drove Leonardo to pursue anatomical knowledge with an intensity and a systematic rigor that went far beyond what any professional artistic need could have required.

He obtained access to human cadavers through hospitals and charitable institutions, most significantly the hospital of Santa Maria Nuova in Florence and the hospital of Santo Spirito in Rome, where unclaimed bodies of paupers and sometimes of executed criminals were made available to those with legitimate reasons for examining them. He apparently dissected somewhere between twenty and thirty complete human bodies over the course of his career, in addition to numerous partial dissections focused on specific anatomical questions, and he supplemented his human investigations with careful dissections of horses, oxen, bears, dogs, and birds, pursuing comparative anatomy as a way of illuminating the underlying principles common to all animal bodies. The conditions under which this work had to be conducted were unpleasant in the extreme. The bodies decomposed rapidly, particularly in warm weather, and Leonardo recorded in his notebooks the difficulties of working in the presence of such decomposition. He was obliged to work quickly and to move from fresh body to fresh body as the conditions required.

His approach to anatomical drawing was a revolutionary innovation in the history of scientific illustration. Rather than depicting a structure from a single fixed viewpoint as earlier anatomical illustrators had done, Leonardo developed a series of techniques that allowed him to convey three-dimensional structural information with unprecedented completeness and clarity. He routinely showed the same structure from multiple angles on the same page or across adjacent pages, allowing the reader to build up a comprehensive three-dimensional understanding of the structure being illustrated. He developed the technique of showing structures in cross-section, cutting through a body or a limb to reveal the internal spatial relationships that could not be seen from any external viewpoint. He used exploded views to show how complex structures were assembled from their component parts, drawing the components separated in space so that their individual forms were clearly visible before showing them assembled in their correct anatomical relationships. All of these techniques, which he essentially invented for the purposes of anatomical illustration, are now standard practice not only in medical and scientific illustration but in engineering drawing and in the technical documentation of complex products of all kinds.

His studies of the human skeleton were models of systematic thoroughness. He examined bones individually and in their assembled relationships to each other, understanding the skeleton as a mechanical system in which the individual bones functioned as levers of various kinds, connected at joints that served as fulcrums, and moved by the muscular forces that were attached to specific points on their surfaces. He made careful studies of the joints, examining the cartilage, the ligaments, the joint capsules, and the synovial cavities with a precision that went far beyond what any previous investigator had recorded. He understood how the shape of joint surfaces determined the range and type of motion possible at each joint, and he analyzed the mechanics of complex joints like the shoulder and the knee with a sophistication that anticipated modern biomechanical analysis.

His cardiovascular studies were in some ways the most forward-looking of his anatomical investigations. He dissected and examined the heart with extraordinary care, making detailed drawings of its chambers, its valves, its internal structure, and the major blood vessels attached to it. To understand how the valves of the heart functioned during the cardiac cycle, he conducted one of the most creative experiments in the history of anatomy, constructing glass models of the aortic root with its associated valve cusps and pumping water and seed material through them to observe the patterns of flow and the behavior of the valve during different phases of the cardiac cycle. From these experiments he reached essentially correct conclusions about the mechanisms by which the heart valves opened and closed, anticipating insights that would not be formally established by physiologists until centuries later. He concluded, furthermore, that the heart was fundamentally a muscular pump whose contractions drove blood through the vessels of the body, a view that challenged the prevailing Galenic theory of his time.

Engineering and Inventions

The engineering designs that fill Leonardo's notebooks represent perhaps the most dramatic and the most widely discussed testimony to the extraordinary creative range of his mind. Among the thousands of pages of his surviving notes are designs for flying machines, underwater diving apparatus, armored fighting vehicles, rapid-fire weapons, hydraulic machinery, canal-digging equipment, textile manufacturing devices, printing improvements, musical instrument innovations, and dozens of other mechanical devices ranging from the practical to the visionary. Some of these designs were realistic engineering proposals based on sound mechanical principles and immediately available materials. Others were brilliant intuitions about the direction of future technical development that could not be realized with any of the tools, materials, or manufacturing capabilities available in his era. And some were purely speculative explorations of mechanical possibility that Leonardo himself probably did not expect to see realized.

His designs for flying machines are the most celebrated and the most frequently discussed of his engineering visions, and they represent his longest and most sustained engagement with a single technical problem. He was captivated by the possibility of human flight from his early years and returned to the subject repeatedly across decades of his intellectual life, approaching it from multiple angles and revising his understanding as his investigations of bird flight and atmospheric behavior deepened. His primary approach was the ornithopter, a machine that would fly by means of flapping wings driven by the muscular effort of a human operator, in direct imitation of the mechanism he believed governed avian flight. He designed multiple versions of ornithopters of varying mechanical complexity, studying how the wing surfaces could be constructed from lightweight materials to create a structure sufficiently large to generate the required lift while remaining light enough for a human to carry.

He also designed a device of a fundamentally different character, consisting of a large helical screw surface rotating rapidly around a vertical axis, which he envisioned as capable of boring into the air and rising in the manner of a screw entering wood. This device, which has often been described as an anticipation of the helicopter, is a genuinely original concept that demonstrates Leonardo's willingness to imagine flight mechanisms quite different from those observed in nature. Whether it would actually have worked is another question; the mechanical problems involved in simultaneously rotating the screw and preventing the body of the machine from spinning in the opposite direction were not ones that Leonardo's design solved.

His military engineering designs were extensive and technically sophisticated, reflecting both his genuine interest in the mechanical principles of weapons and fortification and the practical requirements of the princes and rulers who employed him as a military engineer. He designed armored vehicles whose general description resembles what we now call tanks, large wagon-like platforms surrounded by sloping armor plates with weapons projecting outward from multiple directions, powered by men inside turning cranks connected to the wheels. He designed large crossbows of exceptional power and range, multi-barreled firearms capable of delivering rapid successive shots by rotating a cylinder of loaded barrels into firing position, explosive projectiles for use in cannons, and various devices for destroying enemy fortifications or for defending against attack. He also devoted serious attention to the design of fortifications that would resist the increasingly powerful artillery of his era, developing proposals for low-profile earthwork defenses with sloping faces that would absorb cannon fire rather than being shattered by it.

His hydraulic engineering was perhaps the most consistently practical area of his technical work, in the sense that at least some of his designs were actually implemented in his lifetime or contributed directly to practical projects that were carried out. He designed canal-digging machines intended to excavate channels through soil and rock more efficiently than hand labor alone. He designed water wheels, pumps, sluice gates, and other hydraulic control devices. He worked on practical canal and irrigation projects in the Lombard plain and elsewhere. He developed a proposal, which was seriously considered though ultimately not executed, to divert the course of the Arno River near Florence so as to give the city a navigable water connection to the sea, a project that would have transformed the commercial geography of Tuscany.

His designs for industrial machinery show a systematic understanding of the principles of mechanical advantage, speed conversion, and the translation of rotary into linear motion and vice versa. He designed improved looms for the manufacture of textiles, automated grinding machines, mechanical saws, and other labor-saving devices that anticipated the industrial machinery that would not become practically important until several centuries later. He also thought carefully about the design of measuring instruments, developing proposals for improved compasses, devices for measuring the speed of wind and water, and instruments for use in surveying and navigation.

Nature and the Physical World

Leonardo's relationship with the natural world extended far beyond his professional requirements as an artist or engineer and constituted one of the deepest and most consistent commitments of his entire life. From his earliest childhood explorations of the Tuscan countryside to his late investigations into the catastrophic power of water in flood, he maintained throughout his long career an intense, passionate, and essentially inexhaustible engagement with the phenomena of the natural world in all their diversity and complexity.

His studies of plant life represent one of the less celebrated but in many respects most impressive areas of his scientific work. He observed plants directly and with the same intensity of attention he brought to the human figure, making careful drawings from life that captured the specific visual character of individual species with an accuracy and a sense of living particularity that distinguished them sharply from the schematic, conventionalized plant representations common in the botanical and medical texts of his era. His drawings of flowers, leaves, stems, and roots show an acute understanding of the distinctive structural organization of each species he examined, combined with a sensitivity to the aesthetic qualities of natural plant form that made these studies beautiful as well as scientifically informative.

He was deeply interested in the mathematical regularities that governed the forms of living organisms. He observed the spiral arrangement of leaves on plant stems, recognizing that leaves were placed around the stem in patterns that minimized the degree to which any leaf was shaded by those above it, and he attempted to work out the mathematical rules governing these patterns. He formulated an empirical rule describing the branching structure of trees, observing that the combined cross-sectional area of the branches at any point of division was approximately equal to the cross-sectional area of the parent branch from which they divided, and he connected this observation to the functional requirements of the tree's hydraulic system. He studied the hexagonal cells of honeycombs and investigated the mathematical reasons why this particular geometry was so efficient for the purpose of filling space while using the minimum material for the cell walls.

The flight of birds was a subject of sustained and intense investigation throughout much of his life, motivated primarily by his ambition to design a flying machine but pursued with a thoroughness that went far beyond what any immediately practical purpose required. He spent long hours watching birds in flight, observing with great care how they used their wings, how they controlled their direction and speed, how they exploited air currents and thermals to maintain altitude without continuous effort. He made detailed studies of bird wing anatomy, examining the structure of the feathers, the bones, and the muscles of the wing and trying to understand how each element contributed to the aerodynamic function of the whole. He observed the behavior of birds in winds of different strengths and directions, noting how they adjusted their wing posture and their body attitude to maintain control under varying conditions.

His investigations of atmospheric phenomena were similarly comprehensive. He studied the formation of clouds, the development of storms, the behavior of lightning, the optical properties of fog and haze, the patterns of wind in different topographic settings. He worked out the correct physical explanation for the blue color of the sky, understanding that this was not a property intrinsic to air or to the sky itself but rather an effect produced by the scattering of sunlight by the small particles and droplets present in the atmosphere, an insight that anticipates the formal physical explanation developed by Lord Rayleigh in the nineteenth century. He understood that the moon shone by reflected sunlight and worked out the correct explanation for earthshine, the dim illumination of the part of the moon not directly lit by the sun, as a reflection from the illuminated surface of the earth.

Later Years and France

The fall of Ludovico Sforza's regime in Milan, driven from power by the military intervention of the French king Louis XII, ended what had been the most stable and productive period of Leonardo's working life and inaugurated a phase of greater mobility, less consistent patronage, and in some respects more urgent and concentrated creative activity. He left Milan and spent the subsequent years moving between various Italian cities and courts, always seeking the combination of financial support, intellectual freedom, and practical facilities that would allow him to continue his vast range of investigations and artistic projects. In the last years of his life he settled in France, at the court of King Francis I, in a final chapter that brought him a degree of honor, comfort, and appreciation that had often been elusive in his Italian years.

After the fall of Milan he spent time in Venice, which was considering military engineering projects in response to the Turkish threat, before returning to Florence, where the political environment had changed dramatically since his youth. The Medici had been expelled, the republic restored under various forms, and the cultural atmosphere was different from the confident, Medici-sponsored humanism of his early years in the city. Nevertheless he found both commissions and intellectual stimulation in Florence during this period, and it was almost certainly during his return to Florence that he began work on the Mona Lisa, a project that would occupy him intermittently for years and that he apparently never entirely relinquished.

He also accepted during his Florentine period one of the most ambitious and ultimately most disappointing commissions of his career, a large-scale battle painting for the council chamber of the Florentine government, intended to depict a famous Florentine military victory at the battle of Anghiari. The preliminary work he executed for this project, including a detailed cartoon of the central cavalry engagement that contemporaries found unprecedented in its energy, psychological intensity, and dynamic force, made an enormous impression on everyone who saw it, including the young Michelangelo, who was simultaneously working on a competing battle painting for the same chamber. But the actual mural painting again fell victim to Leonardo's experimental approach to technique, and the work was eventually abandoned, leaving behind only preparatory drawings and enthusiastic contemporary descriptions to suggest what the completed work might have been.

His service to Cesare Borgia as a military engineer during this period brought him into contact with one of the most ruthless and determined political operators in an era not lacking for ruthlessness and determination, and it produced, as a practical byproduct, some of the finest cartographic work of the Renaissance. His detailed bird's-eye-view map of the town of Imola, prepared for Borgia's military planning purposes, is a masterpiece of cartographic precision and representational ingenuity that anticipates modern aerial mapping in its geometric accuracy and its systematic survey methodology.

He returned to Milan after the French reassertion of control over the city and spent additional years there before eventually making his way to Rome, where he worked in a less satisfactory environment under the patronage of Giuliano de Medici, the brother of the reigning pope. The Roman period was frustrating in various ways, and Leonardo found the city's artistic and intellectual environment less congenial than he had hoped, partly because he was now an old man by the standards of his era and partly because Rome was then dominated by the overwhelming presences of Michelangelo and Raphael, both of whom were at the height of their powers and the center of the city's artistic attention.

The invitation from King Francis I of France, young, cultivated, enthusiastically philhellene, and passionately devoted to Italian art and culture, offered Leonardo something he had long sought: recognition of his unique status not merely as a master painter or craftsman but as a universal intellect deserving of honor and material support commensurate with the full range of his extraordinary gifts. He traveled to France in the company of his devoted pupil and companion Francesco Melzi, taking with him his most important paintings and his notebooks, and he settled at the Chateau of Cloux, now known as Clos Luce, a comfortable manor house near the royal residence at Amboise on the Loire River.

Francis visited him regularly and reportedly spent many hours in conversation with the old master, finding in Leonardo a companion whose intellectual range and imaginative capacity matched and stimulated his own considerable intelligence. Leonardo was given the honorary title of First Painter, Engineer, and Architect of the King and received a generous annuity that gave him financial security for the first time in his long career. He continued to work on his notebooks and apparently undertook some technical projects for the French court, including designs for an ideal new royal city and proposals for canal improvements in the Loire valley region.

His health deteriorated during these final years in France, and he suffered a stroke at some point during his residence at Cloux that left him with some degree of paralysis in his right side, though since he was left-handed this did not entirely prevent him from writing and drawing. He was aware that his time was running short and that the vast intellectual projects he had set himself would remain incomplete, and some of his later notebook entries have a quality of urgency and somewhat frustrated summary, as if he were attempting to record his conclusions before the opportunity was lost. He died at Cloux, surrounded by his adopted French household and with Melzi at his side, in the late spring of a year in his mid-sixties. The story that the king was present at his deathbed, holding his head, is almost certainly a later legend rather than historical fact, but it captures something true about the exceptional regard in which Francis held his remarkable guest.

Philosophy and Worldview

To appreciate Leonardo fully as an intellectual and historical figure it is necessary to move beyond the catalog of his accomplishments and attempt to understand the philosophical commitments and the fundamental orientations of mind that unified his extraordinarily diverse activities into a single coherent intellectual life. His notebooks, being the most intimate and direct record we have of his thinking, provide the richest source for this kind of understanding, and they reveal a distinctive and in many respects remarkably original set of convictions about knowledge, nature, and the proper conduct of intellectual inquiry.

At the foundation of Leonardo's intellectual life was a commitment to empiricism so deep and so consistent that it shaped every aspect of his approach to every subject he investigated. He distrusted received authority, whether that authority resided in the writings of ancient philosophers and scientists or in the doctrines promulgated by contemporary scholars. He did not reject learning from texts entirely, and he drew on written sources throughout his career, but he insisted that the primary and most reliable source of knowledge about the natural world was direct observation of that world, and he was willing to reject the testimony of the most venerated authorities when that testimony conflicted with what he himself had carefully observed. His famous assertion that experience was his mistress and his teacher expressed this empirical commitment in its most forthright and provocative form, and his willingness to correct the errors of Galen on the basis of his own anatomical dissections demonstrated it in practice.

His empiricism was not, however, the simple or naive empiricism of a person who simply accumulated observations without theoretical reflection. He understood that observation alone was not sufficient for genuine knowledge, that the raw data of the senses needed to be organized, interpreted, and subjected to rational analysis in order to yield genuine understanding. He believed passionately in the power of mathematics as the language in which nature's deepest regularities were expressed and in which they could be most reliably investigated and communicated. He worked hard, throughout his career, to develop mathematical descriptions and measurements of the phenomena he studied, even when his mathematical preparation was insufficient for the most rigorous treatment of the problems he was attempting. He insisted repeatedly that a study of nature that could not be expressed in mathematical terms was not a genuine science but merely a collection of superficial impressions.

He had a deeply holistic and unified vision of nature that saw all natural phenomena as expressions of a single underlying order manifesting itself in different ways in different domains. He was struck repeatedly by what we might call deep structural analogies between different aspects of the natural world: the similarity between the branching patterns of rivers seen from above and the branching patterns of trees seen from below; the parallel between the pulsating flow of blood through the vessels of the body and the tidal ebb and flow of water in the sea; the resemblance between the layered structure of the earth and the layered structure of the human body with its concentric wrappings of skin, fat, muscle, and bone. These analogies were not merely decorative observations for Leonardo but clues to the underlying unity of natural principles, evidence that the same fundamental laws operated at different scales and in different materials throughout the natural world.

His views on religion and metaphysics were necessarily circumspect given the dangerous intellectual environment of his era, and he expressed them with sufficient care that scholars have disagreed about their precise character. He was not an atheist in any recognizable modern sense, and he clearly regarded the natural world he studied with such passionate attention as in some sense a divine creation, the work of an intelligence vastly greater than his own whose handiwork was visible in every detail of the natural world's structure and organization. At the same time, his commitment to naturalistic explanation, his insistence that natural phenomena had natural causes discoverable by natural means, his willingness to posit geological timescales vastly greater than those implied by scriptural chronology, and his general orientation toward the world as an object of rational investigation rather than devotional contemplation placed him in an uneasy and sometimes tense relationship with the orthodox religious thought of his era.

He had an unusual and in some ways prescient ethical sensibility that extended the circle of moral concern beyond the human community in ways that were genuinely exceptional for his time and place. He was reportedly a vegetarian for much of his life, refusing on ethical grounds to participate in the killing of animals for food, and he was known to purchase caged birds in the market for the specific purpose of releasing them. He expressed in his writings a horror of violence and destruction, though he continued to design weapons and fortifications throughout his career, a contradiction that he seems to have lived with rather than resolved. He was also, according to the accounts of those who knew him, personally generous, good-humored, and possessed of a social warmth and charm that made him welcome in courts and workshops alike.

His attitude toward his own fame and toward the recognition of his achievements was complex and somewhat contradictory. He clearly sought recognition and cultivated the patronage of the powerful with considerable strategic sophistication, yet he also expressed in his private notebooks a contempt for empty celebrity and for the kind of superficial reputation that substituted for genuine achievement. He was capable of considerable irony at the expense of those who valued the appearance of learning over the reality of understanding. He was also, in his private reflections, surprisingly honest about his own failures and frustrations, including his tendency to begin projects he did not complete and his inability to bring to finished published form the comprehensive scientific treatises that he had intended to produce.

Legacy and Historical Impact

The legacy of Leonardo da Vinci extends across so many domains of human activity and has shaped so many aspects of subsequent cultural, scientific, and technological history that any attempt to summarize it comprehensively risks either oversimplification or unwieldy expansion. He influenced the history of painting so profoundly that the entire subsequent development of the European pictorial tradition bears the marks of his innovations. He anticipated scientific and technological developments that were not achieved in practice until centuries after his death. He established a model of the artist as universal intellectual that reshaped the self-understanding of creative people from his own era to the present day. And in the modern world he has become a cultural symbol of unusual power and resonance, an embodiment of the ideal of comprehensive genius, of the possibility that a single human mind operating at its fullest capacity can achieve meaningful insight and genuine mastery across the full spectrum of human intellectual endeavor.

His influence on painting was immediate, profound, and in some respects immeasurable. The technique of sfumato, the softening of edges and the dissolution of contours into atmospheric gradation, was taken up and developed in distinctive ways by the artists who worked directly with him or studied his works carefully, most importantly his pupils Giovanni Antonio Boltraffio and Marco d'Oggiono, but also by artists of the very highest rank who were working independently in his general artistic environment. The young Raphael, who encountered Leonardo's work during his time in Florence and was deeply impressed by it, incorporated into his own mature style the pyramidal grouping of figures, the subtle psychological characterization through gesture and expression, and the atmospheric handling of landscape backgrounds that Leonardo had pioneered. Even Michelangelo, whose artistic temperament was in many ways the opposite of Leonardo's and who reportedly disliked Leonardo personally, was influenced by the example of his contemporary and rival in ways that are visible in certain aspects of his figure painting.

The spread of Leonardo's influence beyond the Italian peninsula was facilitated primarily by the Mona Lisa, which Leonardo brought to France and which eventually became part of the French royal collection and subsequently of the national collection housed in the Louvre. The painting's extraordinary fame grew steadily over the centuries, and it was studied by artists from across Europe who came to Paris to see it. The critical commentary it attracted from the most influential art critics and writers of successive generations, from Giorgio Vasari in the sixteenth century to the great nineteenth-century critics who found in it an embodiment of eternal feminine mystery, contributed to building the extraordinary cultural aura that surrounds it today.

His scientific legacy presents a more paradoxical picture, because of the fundamental fact that his notebooks were not published during his lifetime or for many generations after his death. The notebooks were inherited by Francesco Melzi, who preserved them carefully but did not succeed in organizing or publishing them before his own death. They then passed through various hands, were partially dispersed, and were gradually acquired by libraries and private collectors across Europe. The process of locating, assembling, studying, and publishing the notebooks proceeded slowly and unevenly over several centuries, and it was only in the nineteenth and twentieth centuries that scholars gained a sufficiently comprehensive view of their contents to assess accurately the extent and the significance of Leonardo's scientific achievements.

Because the notebooks were essentially invisible to the scientific community during the period of the scientific revolution, Leonardo's anticipations of later scientific discoveries had no direct influence on those discoveries. The scientists who transformed European understanding of nature between the sixteenth and eighteenth centuries, Copernicus, Kepler, Galileo, Harvey, Newton, and their many contemporaries and successors, did not have access to Leonardo's notes and could not have been directly inspired by them. Many of the insights that Leonardo had reached through his own observation and reasoning had to be reached again independently by these later scientists, who arrived at similar or equivalent conclusions through their own investigations.

The nineteenth century rediscovered Leonardo with particular enthusiasm and with a particular interpretive framework that has continued to shape his popular image ever since. The Romantic movement, with its celebration of individual genius, of the creative power that transcends ordinary human limitations, and of the tragic figure whose visionary gifts were frustrated by a world not yet ready to receive them, found in Leonardo an almost ideal exemplary figure. The discovery and publication of his scientific notebooks reinforced this image, revealing a mind that had understood things about flight, about geology, about the human body, about hydraulics, that the world would not publicly recognize until centuries after his death. This narrative of the unrecognized prophet, the genius born out of his time, is not entirely accurate in its details, since Leonardo was in fact very widely recognized in his own era as an exceptional figure, but it captures something real about the relationship between the depth of his investigations and the capacity of his contemporaries to follow and build upon them.

In the twentieth century and into the twenty-first, Leonardo has become one of the most extensively studied figures in the history of art and science, and the scholarly literature devoted to his life, work, and legacy is by now enormous. Technical examination of his paintings using X-ray photography, infrared reflectography, and other scientific imaging methods has revealed aspects of his painting process, his compositional thinking, and his revisions that were previously invisible. Systematic study of his engineering designs by historians of technology has allowed more accurate assessment of which of his inventions were practically feasible and which were beyond the capabilities of his era. Critical editions of his notebooks, presenting the full text with scholarly commentary and translations, have made his scientific and artistic thinking accessible to readers across the world.

His anatomical drawings, when they were finally published in comprehensive scholarly editions, were received immediately and universally as works of extraordinary and unparalleled achievement, combining scientific accuracy with artistic beauty in a union that has no parallel in the entire history of either science or art. They have been exhibited in the great art museums of the world and studied in medical schools. They have been used to illustrate the history of medicine and the history of art simultaneously. They have inspired artists, scientists, physicians, and engineers, and they have been reproduced in countless publications addressing audiences ranging from professional scientists to school children.

The cultural industry that has grown up around Leonardo is by now immense and shows no signs of diminishing. He is the subject of biographies in every language, the protagonist of novels and films, the inspiration for exhibitions that fill major museums year after year. His most famous images have been reproduced so many billions of times on so many different objects and in so many different contexts that they have become part of the shared visual vocabulary of global popular culture. The Mona Lisa appears on everything from postage stamps to coffee mugs, from high-concept art installations to cheap souvenirs. The Vitruvian Man has become perhaps the most universally recognized symbol of the unity of art and science, of the Renaissance aspiration to understand the human being as a microcosm of the cosmos.

What this extraordinary cultural saturation represents, at its best and most serious, is a genuine and widespread recognition of the significance of what Leonardo achieved and of the continuing relevance of the values and the methods that his life embodied. He demonstrated, more powerfully and more completely than any other figure in the history of human culture, what the fully engaged human mind can achieve when it brings to bear on the world around it the combined resources of careful observation, rigorous analysis, creative imagination, technical mastery, and genuine love of understanding. He showed that the boundaries between art and science, between practical craft and theoretical inquiry, between the making of beautiful things and the investigation of natural truth, are not inherent features of reality but contingent historical constructions that can be dissolved by a mind sufficiently comprehensive and sufficiently committed.

His legacy is ultimately an invitation and a challenge. It invites us to look at the world with greater care and greater curiosity than we are perhaps accustomed to bringing to it. It challenges us to dissolve the artificial divisions between different kinds of knowledge and different kinds of making that we have inherited and to aspire instead to a kind of understanding that is as whole and as integrated as the world it seeks to comprehend. In accepting that invitation and rising to that challenge, each generation discovers anew why Leonardo da Vinci's name has come to stand for the highest possibilities of the human mind and why, more than five centuries after his birth in a small Tuscan hill town, his work and his example continue to inspire wonder, admiration, and the desire to understand everywhere in the world.

The paintings he left behind, small in number but inexhaustible in the depth of attention they reward, the notebooks he filled over decades with his mirror-written reflections and his extraordinary drawings, the stories of his life that have been told and retold in every language and every medium: all of these together constitute one of the richest and most enduring legacies that any individual human being has ever left to the civilization of which he was a part. To study Leonardo is to encounter one of the most completely realized human lives in all of recorded history, a life in which the capacities for seeing, thinking, feeling, and making were developed to a degree that stands as a permanent reminder of what our species is capable of at its most extraordinary. He remains, across all the centuries and all the scholarship and all the legend, a deeply and recognizably human figure, frustrated by unfinished projects and uncertain patronage, insecure about the gaps in his formal education, driven by desires and passions that he sometimes expressed with remarkable candor in his private notes, and possessed throughout his long life of a curiosity about the world so intense and so comprehensive that it still speaks directly and powerfully to anyone who has ever looked at the world carefully and wanted to understand how it works.

The Last Supper: Technique and Meaning

Leonardo's The Last Supper, painted on the refectory wall of Santa Maria delle Grazie in Milan between approximately 1495 and 1498, is one of the most analyzed paintings in human history and presents one of the most consequential technical choices in the history of Western art. The work depicts the moment from the Gospel of John when Jesus announces at the Passover meal that one of his disciples will betray him, and the reactions of the twelve apostles — their gestures, expressions, and groupings — constitute an extraordinarily complex study in human psychology rendered in visual form.

The technical decision that made the work so famous also made it so vulnerable. True fresco requires the painter to apply pigment rapidly to wet plaster, a method that suited the speed and instinct of painters like Michelangelo but was incompatible with Leonardo's meditative, endlessly revised approach. He instead applied tempera and oil on a dry plaster ground, using a preparatory layer of what appears to have been pitch, gesso, and mastic. This experimental technique allowed him the freedom to revise and refine at leisure, but it proved fatally unstable. The surface began to deteriorate within Leonardo's own lifetime, and by the seventeenth century it had deteriorated so severely that a doorway was cut through the lower center of the composition, destroying the feet of the central figure.

Subsequent restorations — there have been at least six major restoration campaigns — each added layers of repainting that complicated the problem without resolving it. The most recent restoration, completed in 1999 after twenty years of painstaking work, stripped away the accumulated layers of earlier restoration to reveal what remains of Leonardo's original work, which is now understood to be fragmentary at best. What we see today is a palimpsest of Leonardo's original intentions, his subsequent revisions, and the interventions of later hands, preserved in conditions of carefully controlled humidity in a sealed room that visitors may enter only in small groups for brief periods.

Despite its physical fragility, the composition has been enormously influential. The grouping of the figures into sets of three, the dramatic use of the doorway-and-windows perspective to create a theatrical stage set that positions the viewer as a participant in the scene, and the psychological differentiation of the apostles' reactions — each individualized in a way that reflects Leonardo's lifetime of observational study of human expression — established conventions for monumental figure painting that dominated European art for centuries.

The Mona Lisa: History and Interpretation

The Mona Lisa, now in the Louvre in Paris and arguably the most famous painting in the world, was probably begun around 1503 and may have been worked on intermittently for several years, possibly until Leonardo's death in 1519. The identity of the sitter has been debated for centuries; the most widely accepted identification is Lisa Gherardini, the wife of a Florentine merchant named Francesco del Giocondo, which explains the painting's Italian name, La Gioconda, and its French name, La Joconde.

The painting's technical innovations were as significant as its eventual fame. The sfumato technique — the soft, smoky gradations between light and shadow that eliminate the hard outlines typical of earlier Renaissance painting — is carried further in the Mona Lisa than in any of Leonardo's earlier works. The atmospheric perspective of the landscape behind the sitter, with its blue-grey mountains receding into haze, represents the most sophisticated deployment of this technique in his surviving oeuvre. The half-length format, with the sitter turned three-quarters toward the viewer and her hands folded in the foreground, became a template for portrait painting so widely adopted that it is now virtually invisible as a convention.

The famous enigmatic smile, which has occupied writers and psychologists since Vasari praised it in the sixteenth century, has been analyzed in terms of everything from Leonardo's personal psychology to the optical physics of peripheral vision. The most technically sophisticated recent analysis suggests that the smile is constructed so that it appears differently when the viewer's eyes focus on different parts of the face — when the eyes focus on the eyes, the mouth appears to smile; when they focus on the mouth directly, the smile seems to recede. This exploitation of the difference between central and peripheral vision, if deliberate, represents an extraordinary degree of understanding of visual perception.

The painting's current celebrity owes more to its theft and recovery than to its intrinsic quality alone. When it was stolen from the Louvre in 1911 by an Italian nationalist named Vincenzo Peruggia — who hid in the museum overnight, removed the painting from the wall, and walked out with it under his coat — the resulting publicity elevated it to a status that no amount of curatorial promotion could have achieved. The painting was recovered in 1913 when Peruggia attempted to sell it to an art dealer in Florence, and its return to the Louvre transformed it into a cultural monument.

Florence and the Second Period

After his years in Milan ended with the fall of Ludovico Sforza and the French invasion of 1499, Leonardo spent several years in circumstances of relative instability that nevertheless produced important work. He briefly served Cesare Borgia as a military engineer in 1502, traveling through central Italy surveying fortifications and territory, and during this period he encountered the young Niccolò Machiavelli, who was on a diplomatic mission to Borgia's court. The encounter between the two most penetrating analytical minds of Renaissance Italy — one concerned with the science of nature, the other with the science of politics — left no direct record but has fascinated historians.

His return to Florence around 1503 brought him into competition and contact with Michelangelo, twenty-three years his junior and already established as a formidable rival. Both artists were commissioned to paint large battle scenes on opposite walls of the Council Hall of the Palazzo della Vecchia — Leonardo was to depict the Battle of Anghiari, Michelangelo the Battle of Cascina. Neither work was completed; Leonardo's, like The Last Supper, was an experimental technical disaster, and Michelangelo abandoned his project to go to Rome to work for Pope Julius II. The preparatory cartoons for both works were studied obsessively by Florentine artists for decades and are known today only through copies.

It was during this Florentine period that Leonardo began work on the Mona Lisa and continued developing his anatomical studies, which reached their greatest depth and systematization in the years around 1508 to 1513. His collaboration with Marcantonio della Torre, an anatomy professor at Pavia, allowed him to dissect cadavers systematically and to develop the diagrammatic conventions for representing three-dimensional anatomical structures that are still used in medical illustration.

Leonardo's Scientific Method and Its Historical Significance

Leonardo's approach to the investigation of nature was in certain respects strikingly modern and in others fundamentally rooted in the assumptions of his time. His insistence on direct observation, his use of experiment to test propositions derived from general principles, and his development of visual representation as a tool for analyzing and communicating complex three-dimensional phenomena all anticipate aspects of later scientific method that would only become systematic in the seventeenth century.

Yet Leonardo was not a proto-scientist in the modern sense. He had no systematic program of investigation, no community of fellow investigators with whom he shared methods and results, and no commitment to publication that would have allowed his findings to contribute to a cumulative body of knowledge. His notebooks remained private during his lifetime and inaccessible for centuries afterward, so that his discoveries could not influence the development of science even when they anticipated later results. His rediscovery of the camera obscura, his understanding of the wave character of sound and light, his anticipation of aspects of plate tectonics and paleontology, and his contributions to fluid mechanics were all lost to the scientific tradition until they were reinvented independently by others.

The notebooks themselves — more than 13,000 pages survive, scattered across libraries in Milan, Windsor, Paris, Madrid, and elsewhere — present a particular kind of intellectual document: the working record of a mind that refused to stop questioning. They move fluidly between observation and speculation, between practical engineering problems and cosmological speculation, between the fine motor control of the surgeon's scalpel and the speculative reach of the philosopher's hypothesis. They are, in their way, one of the most extraordinary intellectual monuments that any individual has left, but their inaccessibility during and after Leonardo's life made them a monument rather than a contribution.

Relationships and Personal Life

Leonardo never married, and the surviving evidence suggests that his primary emotional attachments were to the young men who served as his pupils and assistants. His relationship with Gian Giacomo Caprotti da Oreno, known as Salaì (Little Devil), who joined Leonardo's household around 1490 as a ten-year-old apprentice and remained with him for nearly thirty years, has been the subject of extensive and sometimes tendentious speculation. Leonardo's notebooks describe Salaì's early misdemeanors — stealing, lying, breaking things — with an exasperated affection that suggests both genuine frustration and genuine fondness. Salaì appears as the model in several paintings and drawings, and Leonardo left him money and property in his will.

His second long-term companion was Francesco Melzi, a young nobleman from a family near Milan who joined Leonardo's household around 1506 and remained with him until Leonardo's death, accompanying him to France. Melzi was probably more intellectually congenial to Leonardo than Salaì; he served as secretary and copyist, had artistic training, and after Leonardo's death became the custodian and primary preservationist of the notebooks. It was through Melzi's care, and his subsequent bequest of the notebooks to his heirs, that they survived at all.

Leonardo's sexuality has been discussed since Giorgio Vasari's Lives of the Artists, which was circumspect on the subject, and has become a topic of considerable scholarly and popular attention since the twentieth century. He was charged with sodomy at the age of twenty-four in Florence, along with three other men, in an anonymous denunciation to the magistrates. The charges were eventually dropped for lack of evidence or witnesses, but the episode has been taken as suggestive by many scholars. The broader question of his emotional and sexual life remains, in the absence of direct evidence, a matter of inference and interpretation.