The cathedral, the third to be built in Florence, was built on the site of the previous one, Santa Reparata. It was designed by Arnolfo di Cambio in 1294,with the first stone being laid on September 8, 1296.
In 1329 Andrea Pisano was awarded the commission to design the bronze south doors of the baptistery. The doors, which were completed in 1336 consist of quatrefoil panels, many of which depict scenes from the life of St. John the Baptist.
In 1401, a competition was announced to design the north doors for the baptistery. Seven sculptors competed, including Lorenzo Ghiberti, Filippo Brunelleschi and Jacopo della Quercia, with Ghiberti winning the commission. It took Ghiberti 21 years (1403-1424) to complete these doors. These gilded bronze doors consist of twenty-eight panels, with each depicting a biblical scene from the New Testament. Ghiberti followed this up working on a second set of doors (1425-52), this time with ten panels depicting scenes from the Old Testament. Michaelangelo referred to these doors as the "gates of paradise".
In 1418 a competition was held to design a new dome (or cupola) for the cathedral. The two competitors were Ghiberti and Brunelleschi. Brunelleschi won the competition with his distinctive octagonal design; work started on the dome in 1420 and was completed in 1434.
Artists who have produced work for the cathedral include: