Leonardo was born on 15 April 1452 in or near the hill town of Vinci, in the territory of the Republic of Florence. His birth was recorded by his paternal grandfather, Antonio da Vinci.⁷ He was the illegitimate son of Ser Piero Fruosino di Antonio da Vinci, a twenty-five-year-old Florentine legal notary, and a woman named Caterina. The exact identity and background of Caterina have been the subject of scholarly dispute.⁸ Traditional accounts described her as a local peasant girl who soon married a Vinci lime-burner and farmer named Antonio di Piero Buti del Vacca, nicknamed Accattabriga.⁹¹⁰ In 2017, the art historian Martin Kemp and the researcher Giuseppe Pallanti proposed on the basis of tax records that she was Caterina di Meo Lippi, an impoverished fifteen-year-old orphan from a nearby farmhouse.¹¹ In 2023, the scholar Carlo Vecce advanced an alternative hypothesis based on a 1452 manumission document drafted by Ser Piero, arguing that Caterina was an enslaved woman from the Caucasus region who was freed six months after giving birth.¹² Kemp and other historians contested Vecce's conclusion, maintaining that the rural orphan better fits the archival record.¹³

Leonardo spent his earliest years in his paternal family's home in Vinci and was raised in his father's household. Because of his illegitimate birth, he was excluded from the notary guild and did not receive the formal university education in Latin and Greek typical of his father's profession, receiving instead an informal grounding in vernacular reading, writing, and abacus mathematics. By the mid-1460s, the family had relocated to Florence. Around the age of fourteen, Leonardo entered the Florentine bottega of Andrea del Verrocchio as a studio boy, becoming a formal apprentice by age seventeen. Verrocchio's workshop was one of the foremost artistic and technical centers in Florence, producing paintings, monumental bronze sculptures, and mechanical apparatus, and employing or training painters such as Sandro Botticelli, Pietro Perugino, Domenico Ghirlandaio, and Lorenzo di Credi.¹⁴

By 1472, at the age of twenty, Leonardo qualified as a master in the Guild of Saint Luke, the Florentine association of painters and doctors of medicine. Despite attaining master status, he continued to live and collaborate in Verrocchio's workshop for several more years.¹⁵ His earliest known dated work is a pen-and-ink drawing of the Arno Valley executed in 1473. In painting, he collaborated with Verrocchio on The Baptism of Christ (c. 1470–1475), executing the kneeling angel on the left and parts of the landscape; the sixteenth-century biographer Giorgio Vasari later claimed that Verrocchio was so surpassed by his pupil's handling of oil paint that he resolved never to touch a brush again.¹⁶ During this first Florentine period, Leonardo painted independent works including the Annunciation, the Madonna of the Carnation, the Benois Madonna, and the portrait Ginevra de' Benci (c. 1474–1478).¹⁷

On 9 April 1476, an anonymous denunciation placed in one of Florence's public complaint boxes accused Leonardo and three other young men—including Lionardo de' Tornabuoni, a relative of the ruling Medici family—of sodomy with a seventeen-year-old model and male prostitute named Jacopo Saltarelli.¹⁸¹⁹²⁰ The case was investigated by the Officers of the Night, the municipal tribunal responsible for policing morals.²¹ In June 1476, after two months, the charges against all four men were dismissed for lack of witness testimony and evidence.²² In 1481, the monks of San Donato a Scopeto commissioned Leonardo to paint a large altarpiece, the Adoration of the Magi, which he left in an underpainted state when he departed Florence the following year.²³

In 1482, Leonardo moved to Milan to enter the service of Ludovico Sforza, then regent and later Duke of Milan, where he remained for seventeen years. Seeking to establish himself in a court facing constant military rivalry, Leonardo wrote a letter to Sforza presenting himself primarily as a military engineer capable of designing bridges, siege engines, cannons, and armored vehicles, mentioning only at the close of the letter that he could also paint and sculpt as well as any man. At the Sforza court, he served as principal engineer, architect, pageant designer for ducal festivals, sculptor, and court painter.

Shortly after arriving in Milan, Leonardo was commissioned by the Confraternity of the Immaculate Conception in 1483 to paint the Virgin of the Rocks for a chapel in the church of San Francesco Grande. A prolonged dispute over payment and contract terms led to the creation of two versions: an earlier panel now held in the Louvre in Paris, and a later version, executed between the 1490s and 1508 with workshop participation, now in the National Gallery in London. During the late 1480s, Leonardo also painted court portraits, notably Lady with an Ermine (c. 1489–1491), depicting Sforza's mistress Cecilia Gallerani, as well as the Portrait of a Musician and La Belle Ferronnière.

Throughout his tenure in Milan, Leonardo worked on two monumental projects for Ludovico Sforza. The first, commissioned in 1482, was a colossal bronze equestrian monument to the duke's father, Francesco Sforza, known as the Gran Cavallo.²⁴ Leonardo spent over a decade studying equine anatomy and proportions, constructing a twenty-four-foot-high clay model by 1493 and devising an innovative single-pour casting method to mold seventy tons of bronze.²⁵²⁶ In 1494, however, under threat of invasion, Sforza diverted the bronze to cast artillery cannons. When French forces under King Louis XII invaded Milan and overthrew Sforza in 1499, French archers used Leonardo's full-scale clay model for target practice, destroying it.

The second major commission for Sforza was The Last Supper (1495–1498), painted on the end wall of the refectory of the Convent of Santa Maria delle Grazie in Milan. Rather than using traditional fresco technique, which requires rapid application of pigment onto wet plaster and prohibits later alterations, Leonardo experimented with tempera and oil mediums applied to a dry plaster ground. While this allowed him to build up subtle gradations of light and expression, the surface began to flake and deteriorate within a few years of its completion.²⁷ During his years in Milan, Leonardo also took into his household Gian Giacomo Caprotti da Oreno, who entered the studio in 1490 at age ten and whom Leonardo nicknamed Salaì ("Little Devil"); Caprotti remained Leonardo's companion, pupil, and servant for nearly three decades.

Following the fall of Ludovico Sforza in late 1499, Leonardo fled Milan accompanied by the mathematician Luca Pacioli, traveling first to Mantua—where he drew a profile cartoon of the marquess Isabella d'Este—and then to Venice, where he advised the Venetian Senate on engineering movable dikes and aquatic defenses against Ottoman naval attack, before returning to Florence in 1500.²⁸²⁹ Housed by the Servite monks at the monastery of Santissima Annunziata, he drew a large charcoal cartoon of The Virgin and Child with Saint Anne, which drew crowds of Florentine citizens when displayed.³⁰¹

In 1502, Leonardo entered the service of Cesare Borgia, the son of Pope Alexander VI and commander of the papal armies, as senior military architect and general engineer.³¹ For ten months he traveled across the Romagna and central Italy, inspecting fortresses and pioneering ichnographic cartography, most notably a detailed overhead town plan of Imola that used measured distances and compass bearings. By early 1503 he had returned to Florence, where he collaborated with the republic's chancellery official Niccolò Machiavelli on an unsuccessful engineering project to divert the course of the Arno River away from the rival city of Pisa.

In October 1503, Leonardo began painting a portrait of Lisa Gherardini, the wife of the Florentine silk merchant Francesco del Giocondo—the work known as the Mona Lisa—which he continued to refine for more than a decade and kept with him until his death. At the same time, the Florentine Signoria commissioned him to paint a vast mural, The Battle of Anghiari, measuring approximately twenty-three by fifty-six feet in the Hall of the Five Hundred in the Palazzo Vecchio, directly opposite a companion battle scene assigned to his younger rival Michelangelo Buonarroti. Seeking once again to avoid traditional fresco, Leonardo experimented with an encaustic technique on the wall, which failed to bind properly; he abandoned the unfinished mural when he was summoned back to Milan in May 1506 by the French governor Charles d'Amboise.

From 1506 to 1513, dividing his time between Milan and Florence (where he settled a legal dispute with his half-brothers over the estates of his father, who had died in 1504, and his uncle Francesco), Leonardo served the French crown under Louis XII. Around 1507 he took on a young Milanese nobleman, Francesco Melzi, as his pupil, secretary, and devoted companion. When political instability returned to Milan, Leonardo relocated to Rome in 1513 under the patronage of Giuliano de' Medici, brother of Pope Leo X. Residing in the Belvedere Palace at the Vatican while Raphael and Michelangelo were executing major papal commissions, Leonardo focused on botanical studies, geometry, optical experiments with mirrors, and his final painting, Saint John the Baptist. In 1516, following the French recapture of Milan, King Francis I invited the sixty-four-year-old artist to France, granting him a generous pension, the title of Premier Painter, Engineer, and Architect to the King, and the manor house of Clos Lucé near the royal Château d'Amboise. Despite partial paralysis of his right hand following a stroke, Leonardo designed court pageants and architectural plans for a royal palace at Romorantin until he died at Clos Lucé on 2 May 1519 at the age of sixty-seven.

Leonardo's surviving pictorial oeuvre is small—modern art historians generally accept between fifteen and twenty paintings as wholly or substantially by his hand—yet his formal innovations laid the foundations of the High Renaissance style. His approach to painting was rooted in his conviction that visual art was a science (scienza) grounded in the direct empirical observation of nature, optics, and human psychology. His theoretical notes on light, shadow, perspective, and bodily motion were compiled after his death by his heir Francesco Melzi into the Treatise on Painting (Trattato della pittura).

Among Leonardo's technical contributions was his perfection of sfumato (derived from the Italian for "smoke"), a method of applying multiple translucent glazes of oil paint to eliminate harsh outlines and create imperceptible transitions between light and shade. Combined with his mastery of chiaroscuro—the modeling of three-dimensional form through contrasts of illumination and shadow—and aerial perspective, in which distant landscapes lose clarity and shift toward blue-gray tones due to atmospheric density, sfumato lent his figures an unprecedented lifelike presence.

In composition, Leonardo departed from the rigid profiles and dispersed groupings of Early Renaissance painting in favor of compact pyramidal arrangements and dynamic psychological interaction. In portraits such as Ginevra de' Benci, Lady with an Ermine, and the Mona Lisa, he turned sitters in three-quarter view and used subtle shifts in posture and gaze to convey inner mental states—what he termed the "motions of the mind" (moti mentali). In religious narratives such as the Virgin of the Rocks, The Last Supper, and The Virgin and Child with Saint Anne, figures are linked through unified gestures, intertwining gazes, and continuous spatial environments rather than hierarchical isolation.

Throughout his adult life, Leonardo recorded his daily observations, geometric proofs, anatomical dissections, and mechanical inventions in bound notebooks and loose folios written in left-handed mirror script, running from right to left across the page.³²³³ Upon his death in 1519, he bequeathed these manuscripts to Francesco Melzi; after Melzi's death in 1570, the pages were dispersed, cut apart, and reassembled by later collectors into volumes known as codices. Roughly 6,000 pages survive in institutional and private collections, including the Codex Atlanticus at the Biblioteca Ambrosiana in Milan, the Codex Arundel at the British Library, the Codex Madrid at the National Library of Spain, the Codex on the Flight of Birds in Turin, the Windsor Castle Royal Collection, and the Codex Leicester, which was purchased by Bill Gates at auction in 1994 for $30.8 million.³⁴³⁵

Because Leonardo left many commissions incomplete, frequently collaborated with pupils and assistants in his workshops in Florence and Milan, and rarely signed his works, the exact boundaries of his painted and drawn canon remain hotly debated among connoisseurs, curators, and conservation scientists. Around 1900, nearly one hundred paintings were attributed to him; modern scholarship has pared that list to roughly fifteen to twenty works, while heated controversies surround proposed additions.

The most prominent modern attribution dispute involves Salvator Mundi (c. 1499–1510), an oil-on-walnut panel depicting Christ holding a transparent crystal orb.³⁶³⁷ Long regarded as a heavily overpainted copy by a follower such as Giovanni Antonio Boltraffio—and sold at auction in 1958 for £45—the damaged panel was acquired in 2005 by a consortium of art dealers led by Robert Simon and Alexander Parish and restored by Dianne Modestini. Following its inclusion as an autograph work in the National Gallery's 2011–2012 London exhibition Leonardo da Vinci: Painter at the Court of Milan, the painting was sold at Christie's in New York on 15 November 2017 for $450.3 million, making it the most expensive artwork ever sold at public auction.³⁸ Intelligence and press reports identified the buyer as Saudi Prince Badr bin Abdullah acting on behalf of Saudi Crown Prince Mohammed bin Salman.³⁹ A planned 2018 unveiling at the Louvre Abu Dhabi was indefinitely postponed, and the painting has not been publicly exhibited since the 2017 sale. While scholars such as Martin Kemp and Luke Syson support its attribution to Leonardo, other specialists—including Frank Zöllner, Matthew Landrus, and Carmen Bambach—argue that the work was primarily executed by workshop assistants with at most partial participation by Leonardo, or that extensive restoration precludes definitive judgment.⁴⁰

A second major dispute centers on La Bella Principessa, a mixed-media portrait in colored chalks and ink on vellum sold at Christie's in 1998 for under $22,000 as an early nineteenth-century German school pastiche and purchased in 2007 by collector Peter Silverman.⁴¹⁴² Kemp and French engineer Pascal Cotte attributed the drawing to Leonardo, proposing that it depicts Bianca Sforza, the illegitimate daughter of Ludovico Sforza, and was excised from a 1496 Milanese vellum volume, the Sforziada, held in Warsaw.⁴³ Numerous museum curators and drawing specialists rejected the attribution on stylistic and technical grounds, and the National Gallery declined to include it in its 2011 exhibition.⁴⁴ In 2015, the convicted British art forger Shaun Greenhalgh claimed in his memoir that he had fabricated the portrait in 1978, though radiocarbon and lead-white pigment testing indicated the materials were at least 225 to 250 years old.

Scientific efforts have also turned toward Leonardo's physical remains and genetic lineage.⁴⁵⁴⁶ Leonardo was originally buried in the collegiate church of Saint-Florentin at the Château d'Amboise, which was demolished during the French Revolution and early nineteenth century; skeletal fragments excavated at the site in 1863 were reinterred in the château's smaller Chapel of Saint-Hubert, where an inscription explicitly describes them as "presumed remains".⁴⁷ Launched in 2016, the international Leonardo da Vinci DNA Project has worked to verify these remains and authenticate disputed artworks through genetic sequencing.⁴⁸ In 2021, genealogists Alessandro Vezzosi and Agnese Sabato traced a continuous 690-year male lineage from Leonardo's family across twenty-one generations, identifying fourteen living male relatives carrying the family's Y chromosome.⁴⁹ By early 2026, project researchers had expanded the list to fifteen living male descendants and reported isolating male human DNA linked to a Tuscan lineage from both a family letter and a disputed 1470s red-chalk drawing, Holy Child, though a definitive genetic match to Leonardo himself remains unconfirmed.