Basilica of Saint Mary of the Flower is the main church of Florence, Italy. Il Duomo di Firenze, as it is ordinarily called, was begun in 1296 in the Gothic style to the design of Arnolfo di Cambio and completed structurally in 1436 with the dome engineered by Filippo Brunelleschi. The exterior of the basilica is faced with polychrome marble panels in various shades of green and pink bordered by white and has an elaborate 19th-century Gothic Revival facade by Emilio De Fabris.
The cathedral complex, located in Piazza del Duomo, includes the Baptistery and Giotto's Campanile. The three buildings are part of the UNESCO World Heritage Site covering the historic centre of Florence and are a major attraction to tourists visiting the region of Tuscany. The basilica is one of Italy's largest churches, and until development of new structural materials in the modern era, the dome was the largest in the world. It remains the largest brick dome ever constructed.
Santa Maria del Fiore was built on the site of an earlier cathedral dedicated to Saint Reparata. The ancient structure, founded in the early 5th century and having undergone many repairs, was crumbling with age, as attested in the 14th century Nuova Cronica of Giovanni Villani, and was no longer large enough to serve the growing population of the city. Other major Tuscan cities had undertaken ambitious reconstructions of their cathedrals during the Late Medieval period, as seen at Pisa and particularly Siena where the enormous proposed extensions were never completed.
The cathedral of Florence is built as a basilica, having a wide central nave of four square bays, with an aisle on either side. The chancel and transepts are of identical polygonal plan, separated by two smaller polygonal chapels. The whole plan forms a Latin cross. The nave and aisles are separated by wide pointed Gothic arches resting on composite piers.
By the beginning of the 15th century, after a hundred years of construction, the structure was still missing its dome. The basic features of the dome had been designed by Arnolfo di Cambio in 1296. His brick model, 4.6 metres (15 ft) high, 9.2 metres (30 ft) long, was standing in a side aisle of the unfinished building, and had long ago become sacrosanct. It called for an octagonal dome higher and wider than any that had ever been built, with no external buttresses to keep it from spreading and falling under its own weight.
The three huge bronze doors date from 1899 to 1903. They are adorned with scenes from the life of the Madonna. The mosaics in the lunettes above the doors were designed by Niccolo Barabino. They represent: Charity among the founders of Florentine philanthropic institutions; Christ enthroned with Mary and John the Baptist; and Florentine artisans, merchants and humanists. The pediment above the central portal contains a half-relief by Tito Sarrocchi of Mary enthroned holding a flowered scepter. Giuseppe Cassioli sculpted the right-hand door.