When young Leonardo joined his father in Florence, perhaps soon after 1465, after his grandfather’s death, Ser Piero had already achieved an excellent social position in the city. Around 1469 he rented a house owned by the Wool Guild right in the city centre (where Piazza San Firenze now stands, a stone’s throw from the Palazzo della Signoria). In 1470 Piero became procurator for the large convent of Santissima Annunziata and his tax returns for the following years clearly confirm that the family’s property and wealth grew. The positions he held became increasingly prestigious and he soon started to work for the Florentine government itself in the Palazzo della Signoria. Even if Vasari was probably exaggerating when he described Piero as a friend of Lorenzo the Magnificent, there is no doubt that Leonardo’s father frequented the right circles and knew the artists patronized by the Medici.
One of them was Andrea del Verrocchio, a figure who epitomized that brilliant Florentine society, midway between creative craftsmanship and the most advanced scientific research in Italy. Born in 1435 to a humble furnace worker, Andrea had become an apprentice goldsmith in one of the city’s workshops, where he learned the complex procedure of handling molten metals and forming the clay models to be cast in gold. When the workshop where he trained was faced with a shortage of work, Andrea switched to sculpture, being described as a scarpellatore [‘stone carver’] in the catasto of 1457 [sc. the census of Florence and its subject territories made for tax purposes]. In his tax return of that same year, Andrea, who was not handsome but was a pleasant-looking man, made a disconcertingly honest declaration about his business and private finances. It reveals his extraordinarily compassionate nature as someone who not only refused to collect the small rentals owed by his tenants, but even justified their arrears by stating that they were so poor they could not afford to pay.
I am owed as much by various individuals, poor people who never have anything. I find myself at the age you see and with little business. I used to work with the goldsmith but because there is no work I am no longer there. My said brother works with Romolo Cechi, weaver, and is an apprentice on a salary, and we cannot earn our hose.6
Nowadays we imagine that an artist’s life must have been splendid in view of the fabulous legacy of the art that has survived, but in fact it was never free from the hardships of day-to-day survival. The workshop that Leonardo would join, about ten years after his earliest experiments with art, was a modest place in terms of equipment and earnings, yet it was at the cutting edge of technology for its day, at least with regard to metal casting. Many clues have survived of Andrea’s good character: he appears to have dedicated his entire life more to others than to himself. He never abandoned his sister’s orphaned children and never married, choosing instead to live together with his young pupils. It is indeed possible that this choice concealed a more ambiguous sentimental inclination, given that Andrea left almost all his inheritance to his closest pupil, Lorenzo di Credi, much to the fury of his own brother, who impugned the will. Despite such an unpromising start, Andrea was destined to make a profound mark on Renaissance art, even without taking into account the major contribution he made to young Leonardo’s training.
Now that studies of the Florentine Quattrocento have moved beyond Vasari’s legends and have returned to original documents, it can safely be said that the fame achieved by Andrea’s pupil Leonardo has undermined and cast a shadow over that of the master. Indeed, Andrea del Verrocchio was a man of such talent, endowed with such a broad outlook, that it is impossible to imagine Leonardo without him. The master’s teaching and interests contained (almost) all the topics that would later be expanded by Leonardo. But this generous master deserves the greatest credit for having accepted and protected the young man from the countryside for many years, and for offering his own affection to fill the vacuum left by Ser Piero – who, although living only a few hundred yards from his son, never welcomed him into his house and effectively treated him as an outsider. In Florence, Leonardo also felt the heavy burden of his stepmother’s sterility. Francesca di Giuliano Lanfredini, who was also from an excellent family, became Ser Piero’s second wife in 1465; but, despite her youth, she was unable to have children. Not accepted at his father’s house, Leonardo found family warmth and enthusiasm in Andrea del Verrocchio’s workshop.
According to the story told by Vasari, now blended with the myths surrounding Leonardo, Verrocchio appears as a self-made genius who had virtually nothing to learn, because such genius manifests itself as a fully formed gift. Of course, nothing could be further from the truth. Starting from his humble beginnings as a scarpellatore and with nothing but his immense talent and a capacity for self-denial, Andrea embarked in the 1460s on a career that would be first recognized in Florence before he moved to the splendid and wealthy city of Venice – where he died while working on his most famous work, the equestrian monument to Colleoni.
In 1470, soon after Leonardo’s arrival, Verrocchio’s workshop was already the forge of artistic avant-garde initiatives in Florence, and the master was commissioned to cast one of the most representative works of the Florentine Renaissance: the bronze group of Christ and Saint Thomas in one of the external niches of Orsanmichele. Above all, it was representative because it was a major technical challenge: Verrocchio cast both the Christ figure (except perhaps the lifted right arm) and that of Saint Thomas in one single piece.
At the time, this was the hardest technical challenge for an artist, given that such large figures had not been cast in a single piece since classical times. Even Donatello, who had made large bronze statues, had cast the individual parts before cold-welding them together with the help of rivets. The problem of casting is that a layer of wax has to be inserted between the plaster mould and the negative model made from refractory clay. Under the pressure of hot metal, the wax layer melts and flows out of special drainage vents, leaving space for the molten alloy to reach into all the corners before hardening. The task is extremely difficult because the metal has to be poured at extremely high temperatures and if it cools along the way many parts remain unfilled. In his model, Verrocchio highlighted the folded, plastic forms, creating any number of recessed surfaces that were much more difficult to reach than a smooth surface.
The apparatus that needed to be prepared for casting was one of those industrial machines whose success was based on an understanding of mechanics, physics and chemistry and on exceptional design skills. In spite of his humble origins, Verrocchio achieved a previously unparalleled level of engineering skills, so much so that his reputation immediately burgeoned and the Opera del Duomo [the Works Committee for the Cathedral] placed him in charge of completing the other masterpiece of Florentine engineering: Brunelleschi’s cupola. In particular, he was commissioned to cast a huge bronze ball for the lantern.
Verrocchio’s creativity and skill did not go unnoticed by the Medici, who commissioned him to carry out a number of high-profile public works, for example the funerary monument to Cosimo the Elder, the founder of the dynasty, in the church of San Lorenzo. In this work Verrocchio, the son of a poor furnace worker, interpreted the sober elegance possessed by Cosimo even in politics, and his complete absence of ostentation, by creating a superb interlaced grille, beneath which lies a simple but stark tomb that evokes the passage to the next world of a man of acknowledged public virtue. Here too the perfect technology of the casting is evident in the grille, which is made from carefully interlaced rhombi: an almost metaphysical image that allows a glimpse into an empty space symbolizing the everlasting void beyond death. In both of these bronze monuments Verrocchio achieved such perfection that there is an almost complete absence of the retouching and chiselling used by all artists before him to conceal their technical flaws.
The excellence of Verrocchio’s casting technique during this period led him into a sector that seemed far removed from his core skills: ballistics. These were years when new types of firearms were being experimented with and the secret of good casting was essential to their success. Therefore we should not be too surprised to learn from financial documents that, around the years when Leonardo, not yet 15, joined the workshop, Andrea Verrocchio was called upon to make military bombards, one of which – certainly not the first – would be delivered to Pisa in 1484.
Verrocchio’s interests in engineering and ballistics are enough to explain Leonardo’s interest in the science of firearms, a skill he offered to the duke of Milan. The origin of Leonardo’s interests and knowledge can therefore be traced to Andrea’s workshop, where the young man witnessed the creation of all those fantastic and wondrous new offensive weapons. The master founder’s library contains some important literary texts that confirm the circularity among artistic ideas and general philosophical and literary ideas in Florence during this period, as well as the proximity and interaction between the various fields of knowledge. The short circuit between art, science and philosophy that sparked the mind of a boy freshly arrived from the Florentine countryside was triggered in Verrocchio’s workshop.