Florentine authorities laid the first stone of what would become the Duomo, commissioning architect Arnolfo di Cambio to design a cathedral grand enough to rival those of Florence's rival cities. The dome itself would not be completed until 1436, when Filippo Brunelleschi solved an engineering puzzle that had stumped architects for generations.
Florence in 1296 was a wealthy trading and banking city eager to announce its status through architecture. City fathers wanted a cathedral that would outshine the offerings of Pisa and Siena, and Arnolfo di Cambio, already known for his work on the Palazzo Vecchio, was given the commission for what would be one of the largest churches in the Christian world.
Progress was slow and repeatedly interrupted by plague, war, and financial trouble, including the devastating Black Death of 1348. By the time the nave and walls were finished in the early 15th century, nobody actually knew how to build the enormous octagonal dome the design called for -- no one had constructed a dome of that span since antiquity, and the usual method of wooden scaffolding support was impossible given the opening's width.
Filippo Brunelleschi eventually won a competition to solve the problem, devising an ingenious double-shell herringbone brick pattern and inventing new hoisting machines to lift materials without conventional scaffolding. The dome, completed in 1436, remains the largest brick dome ever built and a defining symbol of the Renaissance's confident marriage of engineering and art.
Key people: Arnolfo di Cambio, Filippo Brunelleschi