quality:corruption, stylistic:style_transfer
Verrocchio's workshop

In the mid-1460s, Leonardo's family moved to Florence, which at the time was the centre of Christian Humanist thought and culture. Around the age of 14, he became a garzone (studio boy) in the workshop of Andrea del Verrocchio, who was the leading Florentine painter and sculptor of his time. This was about the time of the death of Verrocchio's master, the great sculptor Donatello. Leonardo became an apprentice by the age of 17 and remained in training for seven years. Other famous painters apprenticed in the workshop or associated with it include Ghirlandaio, Perugino, Botticelli, and Lorenzo di Credi. Leonardo was exposed to both theoretical training and a wide range of technical skills, including drafting, chemistry, metallurgy, metal working, plaster casting, leather working, mechanics, and woodwork, as well as the artistic skills of drawing, painting, sculpting, and modelling.

Leonardo was a contemporary of Botticelli, Ghirlandaio and Perugino, who were all slightly older than he was. He would have met them at the workshop of Verrocchio or at the Platonic Academy of the Medici. Florence was ornamented by the works of artists such as Donatello's contemporaries Masaccio, whose figurative frescoes were imbued with realism and emotion, and Ghiberti, whose Gates of Paradise, gleaming with gold leaf, displayed the art of combining complex figure compositions with detailed architectural backgrounds. Piero della Francesca had made a detailed study of perspective, and was the first painter to make a scientific study of light. These studies and Leon Battista Alberti 's treatise De pictura were to have a profound effect on younger artists and in particular on Leonardo's own observations and artworks.

Much of the painting in Verrocchio's workshop was done by his assistants. According to Vasari, Leonardo collaborated with Verrocchio on his The Baptism of Christ (c. 1472–1475), painting the young angel holding Jesus's robe with skill so far superior to his master's that Verrocchio purportedly put down his brush and never painted again (the latter claim probably being apocryphal). The new technique of oil paint was applied to areas of the mostly tempera work, including the landscape, the rocks seen through the brown mountain stream, and much of Jesus's figure, indicating Leonardo's hand. Additionally, Leonardo may have been a model for two works by Verrocchio: the bronze statue of David in the Bargello and the archangel Raphael in Tobias and the Angel.

Vasari tells a story of Leonardo as a very young man: a local peasant made himself a round buckler shield and requested that Ser Piero have it painted for him. Leonardo, inspired by the story of Medusa, responded with a painting of a monster spitting fire that was so terrifying that his father bought a different shield to give to the peasant and sold Leonardo's to a Florentine art dealer for 100 ducats, who in turn sold it to the Duke of Milan.