Getting Off to a Good Start
Leonardo's period with Verrocchio (1468–1472) was his first foray into the real world of professional art. While apprentices often worked with their masters on commissioned projects, most of these students didn't go on to outshine their teachers! Then again, most of the students weren't Leonardo da Vinci, either.
The Baptism of Christ
The first real tip-off to Leonardo's talents came when he worked on a painting called The Baptism of Christ, completed in 1472. Andrea Verrocchio was the official painter, but it was one of the first commissioned works in which Leonardo took part. The monks from the Florentine church of San Salvi requested the painting, and many members of Verrocchio's studio worked on it. Though apprentices like Leonardo had to do office duty and other routine tasks, they also got to help on the master's jobs.
In this painting, Verrocchio probably painted Christ and John the Baptist. Although written documentation is slim, it's thought that da Vinci's particular addition to the painting, along with some of the landscape, was a kneeling angel supporting the mantle. This figure appears more lifelike than the others; the angel's expression, hair, and clothing are particularly detailed. The angel in question was also painted in oil, Leonardo's paint of choice, whereas much of the remainder of the painting was done in tempera. And remember, Leonardo much preferred oil paint because it allowed subtle variations in the colors that just weren't possible with tempera.
Reactions of the Master
Using diagnostic technology to examine this painting, historians have essentially proved that Verrocchio did a master sketch before applying paint. From these tests, you can see that Leonardo strayed from this overall scheme and took liberties with his portion of the painting. You can also see that Leonardo's rendering of the landscape, full of shadows and bright sunlight, is different from the parts Verrocchio painted. Even at this early point in his career, Leonardo was using his own creativity and invention rather than simply following orders. That kind of attitude only worked, though, because he was so highly skilled to begin with. Still, we'll never know if Verrocchio was angry or pleased with Leonardo's changes to his initial design.
While Verrocchio's work didn't exactly pale in comparison to Leonardo's, it was clear even from his early work that Leonardo's painting abilities would eventually surpass those of his master. In fact, one story (that may or may not be true) has it that Verrocchio actually swore to give up painting when he saw Leonardo's work, since he knew he could never be that good! But even if that story were true, Verrocchio was an artist skilled in many areas, and he could just as easily have focused his talents on metalsmithing, sculpture, and bronzing. Fortunately for Verrocchio's ego, Leonardo didn't develop his skills in those areas until later.
Study it First!
Leonardo often made clay study-models of figures before committing them to canvas or wood. In the case of the angel in this painting, Leonardo probably first made a model of clay and then painted the model; this approach would have made the final drawing seem more accurate. This technique might explain the apparent stiffness in the folds of the cloth draping Leonardo's angel, but it speaks volumes about Leonardo's willingness to experiment. And of course Leonardo was right—the best way to learn to paint something is to study it in three dimensions!
Collaborative Effort
Besides Verrocchio and Leonardo, a number of other particularly well-known collaborators, including Sandro Botticelli and Lorenzo di Credi, were involved with the creation of The Baptism of Christ. Many of these artists would eventually become famous in their own rights. This masterpiece remained at the monastery in San Salvi until 1530, and it currently resides in the Uffizi Gallery in Florence.

Leonardo's apprenticeship in Verocchio's studio lasted until about 1472. At that time he was admitted to the Company of Painters, Florence's painting guild. Probably eager to test the waters on his own, Leonardo had the opportunity to branch out as an independent artist. But he didn't give up all ties to Verrocchio's workshop, probably because he wanted to further his education and continue his association with the master.
Collaboration on paintings was not uncommon at this time; a patron might provide the general direction for a piece of art, and sometimes entire studios (masters and apprentices) would work together on a single painting. In addition to Leonardo's assistance on The Baptism of Christ in 1472, he collaborated with Verrocchio on other works, including the Madonna di Piazza (1474). Though Leonardo must have gradually evolved from a student to an equal in Verrocchio's eyes, he didn't really come into his own until he finally started working alone.

