The construction of the Cathedral, dedicated to Santa Maria del Fiore, fù begun in 1294 by Arnolfo di Cambio at the behest of the authorities and of citizenship, desirous not only of a cathedral wider than the previous church of Santa Reparata, but that was provided with the "most high and sumptuous magnificence" and which exceeded in beauty and size the cathedrals of rivals Tuscan cities. The new cathedral was erected around the oldest church, which incorporated the simple structures and the two bell towers; finally, in 1375, Santa Reparata was demolished, but long the florentines continued to call the new Duomo with its ancient name (had to intervene the authorities with heavy fines, to impose one of Santa Maria del Fiore). The lower part of Santa Reparata, remained buried under the floor of the cathedral until recent times, can be visited today by descending a ladder from the right aisle; there are remains of frescoes, sculptures and tombstones: among other that of Filippo Brunelleschi. The spacious, bright and solemn interior of the Cathedral was the theater of fiery sermons of Gerolamo Savonarola and bloody Pazzi conspiracy. On 26 April 1478 Some members of the Pazzi family, hostile to the doctors, in secret agreement with Archbishop Salviati aggredirono Lorenzo the Magnificent and his brother Giuliano during Mass; Lorenzo managed to escape but Giuliano was killed and to the conspiracy followed a fierce repression. There are many works of art reached over the centuries to embellish the cathedral, which still maintains a severe aspect with its polistili pillars and the high ogival arches. In the counter-facade stands out the quadrant of a large clock, performed in 1443 and adorned by four heads of prophets painted by Paolo Uccello. Even Paolo Uccello is the fresco with the funeral monument of Giovanni Acuto on the wall of the left aisle (1436); next to it is the funeral monument of Niccolò da Tolentino, Andrea del Castagno (1456). The large octagonal tribune is overhung by the dome designed by Brunelleschi. The competition for the construction of the dome was held in 1418. They were immediately evident to the company's difficulties due to the inadequacy of systems traditional building. Brunelleschi designed a unique system of mobile arches that allowed you to exceed the usual system to fixed structures starters from the ground (manifestly not adoptable for the enormous size of the building) and succeeded so to prevail on the eternal rival, Lorenzo Ghiberti, who was also present in the contest. The dome, closed until the lantern in 1436, is founded on a mighty octagonal drum, travelled by RIBS in marble and covered with red tiles cooked in the ovens of the lmpruneta. Inside the dome bears a fresco decoration of Giorgio Vasari and Federico Zuccari (1572-79) depicting the Last Judgment in five overlapping areas. The main altar is dominated by a wooden crucifix of Benedetto da Maiano; around is the octagonal choir of Baccio Bandinelli (1555), decorated with reliefs. Behind the altar, on the right is the Old Sacristy. That lunette above the entrance an ascension in terracotta by Luca della Robbia. On the opposite side of the tribune, symmetrically, is the New Sacristy, which gives access to a beautiful bronze door of Luca della Robbia , Michelozzo and Maso di Bartolomeo (1445-69); in the lunette a resurrection, yet Luke; inside, beautiful inlaid wardrobes fifteenth. In the chapel at the bottom of the apse is the urn ghibertiana in bronze with the relics of S. Zenobius.