Santa Maria del Fiore was constructed on the site of the old cathedral of Santa Reparata, which had been built in the time of Bishop Zanobius in the early decades of the 5th century. The initial project was to enlarge the original cathedral, but in 1294 the Council of the Hundred opted for a completely new construction.
In 1296 the foundation stone for the new cathedral was laid and dedicated to the Virgin with the name of Santa Maria del Fiore. The architect was Arnolfo di Cambio. The old cathedral continued to be used while the new one was being constructed, but finally, in 1375, it was definitively buried. Arnolfo died in 1331 or 1332, which slowed down work, until the Arte della Lana, the most powerful guild in Florence, nominated Giotto as master of works, and he began work on the construction of the nearby bell tower.
Giotto died in 1337 and others, including Francesco Talenti, took charge of the Duomo project.
The cathedral was completed in 1415, with the exception of the dome, which was designed by Brunelleschi, who produced an engineering masterpiece. It was erected in just 15 years; first of all a bronze ball created by Verrocchio was put on top of it, and then a cross, also in bronze. Pope Eugenio IV consecrated the cathedral in 1436 on the occasion of the Council of Florence which was then underway.
The facade (the one we see today) was redone in the 19th century according to a design by Emilio de Fabris.
The interior has many monuments and other works of art, including the monument to Giotto by Benedetto da Maiano, the portrait of Dante by Domenico di Michelino (based on a drawing by Baldovinetti), and a tondo with a bust of Brunelleschi by Andrea Cavalcanti. The clock dial is by Paolo Uccello and the round glass windows were based on a cartoon by Ghiberti. The holy water stoup (now a copy) is dated circa 1380.
Behind the main altar by Baccio Bandinelli, to the left, there is the sacristy, where Lorenzo the Magnificent took refuge during the Pazzi Conspiracy in 1478.
In the subterranean area below Santa Maria del Fiore, it is possible to visit the old cathedral of Santa Reparata.
The duomo of Florence, 153 metres long and 38 wide, is the fourth-largest Christian church.
Like the cathedrals of Florence's rival cities, Santa Maria del Fiore was built with a Latin cross plan, with a basilica nave, three vast arms, and a dome; the latter starts 50 metres from the ground.
The cathedral looks out onto a large piazza called Piazza del Duomo, where the traditional rite of the Scoppio del Carro is conducted every year at Easter.