The Opera di Santa Maria del Fiore was founded by the Florentine Republic in 1296 with the participation of the city's ecclesiastical authorities to oversee construction of the new cathedral and its bell tower.
Notes from Cathedral of Santa Maria del Fiore: Santa Maria del Fiore , whose construction was designed by Arnolfo di Cambio, is the third church in the world (after San Pietro in Rome, San Paolo in London) and the largest in Europe at the time of its completion in the 15th century: it is long 153 meters, 90 meters wide at the cross and 90 meters high from the floor at the lantern opening. It, the third and last Florentine cathedral, was entitled in 1412 to Santa Maria del Fiore with a clear allusion to the lily, the symbol of the city.
It was built over the second cathedral, which early Christian Florence had dedicated to Santa Reparata.
The remarkable differences of style revealed in its parts are the testimony of the variation of taste in the long period between its foundation and its completion.