Traditionally, the upper part of the façade was believed to have been completed in the 1370s under the direction of Giovanni di Cecco. However, it is now believed that the work was completed as early as the beginning of the century, in the 1310s.
The mosaics on the facades were made in 1878 by Luigi Mussini (central) and Alessandro Franchi (side)
The time of construction of the Campanile is not known for certain, but it was completed after the dome (some sources say 1313).