In 1418, the cathedral committee of Florence had a problem. The cathedral, Santa Maria del Fiore, had been under construction for over a century, and the central crossing was meant to be covered by the largest dome since Roman antiquity. Nobody knew how to build it. The hole in the roof was 42 metres across. The masonry techniques that worked for smaller domes did not scale.
The committee held a competition. The winning entry was submitted by Filippo Brunelleschi, a goldsmith with no formal training in architecture and an unproven theory about how to assemble a self-supporting double-shell dome without using the centring (the wooden scaffolding) that all previous large domes had required. The dome was completed in 1436. It is still the largest brick dome ever constructed.
Why Florence
Florence in 1400 was not the largest Italian city. It had perhaps 60,000 people. Milan and Venice were larger, Naples was larger, Rome was politically more important. What Florence had was money. The Florentine guilds, particularly the Arte del Cambio (the bankers' guild) and the Arte della Lana (the wool merchants' guild), had accumulated wealth from international trade and finance. The Medici bank, founded by Giovanni di Bicci de' Medici in 1397, would soon become the largest financial institution in Europe.
The wealth was concentrated in a small number of families, but it was deployed publicly. Florentine guilds competed to fund civic projects: the bronze doors of the Baptistery, the statues for Orsanmichele, the cathedral itself. The competition was not entirely about religion. It was about civic identity. A guild that funded a major artwork demonstrated its standing in the republic.
The Three Inventions
Three technical innovations developed in early fifteenth-century Florence transformed European art for the next three centuries.
The first was Brunelleschi's rediscovery of linear perspective, the geometric system for representing three-dimensional space on a two-dimensional surface. Brunelleschi conducted public demonstrations in the Piazza del Duomo around 1413, using a small painted panel and a mirror to show how the system worked. The painter Masaccio applied the technique to his frescoes in the Brancacci Chapel within a decade.
The second was the bronze-casting revival led by Lorenzo Ghiberti and Donatello. Ghiberti spent fifty years on the two sets of bronze doors for the Baptistery, the second of which Michelangelo later called the Gates of Paradise. The technique of casting large bronze statues had been largely lost since antiquity. The Florentine workshops rebuilt it.
The third was the systematic study of human anatomy through dissection. The practice was not officially permitted but was widely practised. Artists worked alongside doctors. The result was a generation of painters and sculptors who understood the underlying structure of what they were depicting.
The Medici
Cosimo de' Medici (1389 to 1464) and his grandson Lorenzo (1449 to 1492) made the Medici bank the most powerful financial institution in Europe and used the proceeds to fund a generation of artists. Botticelli, Verrocchio (Leonardo's teacher), Michelangelo, and several others worked under Medici patronage at various points.
The patronage was not pure connoisseurship. The Medici used commissioned art as political instruments. Botticelli's Primavera, painted around 1480, was commissioned for the Medici villa at Castello and shows a complex allegory drawing on classical mythology, contemporary humanist philosophy, and Medici family symbolism. The painting served simultaneously as decoration, intellectual statement, and dynastic display.
The Medici fell from power in 1494 when the French invaded Italy and the Florentine republic temporarily expelled them. The Dominican friar Savonarola briefly turned Florence into a theocracy, organising bonfires of "vanities" that destroyed paintings, books, and luxury objects. Botticelli is said to have thrown some of his own works on the fires. Savonarola was executed in 1498. The Medici returned to power in 1512.
Donatello and the Public Statue
Donatello's bronze David, made for the Medici palace courtyard probably in the 1440s, was the first freestanding nude bronze cast since antiquity. The figure is small (158 cm tall), wears nothing but a hat and boots, and stands with one foot on the severed head of Goliath. The pose is contrapposto: weight on one leg, the other relaxed, hips and shoulders set at slight angles to each other. It is a posture borrowed directly from classical Greek and Roman sculpture.
The political symbolism was clear. Florence was David, the small republic that defeated giants. Goliath was whichever foreign power most recently threatened the city: Milan, the Papacy, the French. The statue made the Medici, who privately owned it, the patrons of the city's self-image.
Why Florence and Not Elsewhere
Other Italian cities had wealth, patrons, and skilled craftsmen. What Florence had that they did not have was a particular combination of conditions: a republican government that encouraged guild competition; a strong tradition of civic patronage; a small enough population that the leading artists, patrons, and intellectuals all knew each other personally; and a few decades of relative political stability in the early fifteenth century during which the new ideas could take root.
Once the Renaissance was established in Florence, it spread rapidly to Rome (where the popes hired Florentine artists for major commissions), Milan (where Leonardo went to work for the Sforza), and Venice (which developed its own distinct school). By 1500, the Renaissance was a pan-Italian phenomenon. By 1520, the Italian wars and the Sack of Rome in 1527 had effectively ended its first phase.
But the dome was still standing. It is still standing now. The hole in the roof was solved, and the city that solved it became the place where the rest of European art history began.
