The marble cladding and the decoration of the side entrances continued apace in the meantime, leading to the erection of the Porta dei Canonici to the south and the Porta della Mandorla to the north, the latter being crowned by a relief of the Assumption of the Virgin (1414–21), a graceful work by Nanni di Banco.
The other two doors are no less elegant: the door of the bell tower to the south, in the second bay, has relief work by the school of Andrea Pisano, while the Porta della Balla to the north was named after an old gate in the city walls leading out to the Borgo di Balla (now Via dei Servi) where the Arte della Lana had its drying sheds.
The cathedral's dignified east end consists of three large tribunes lit by Gothic two-light windows. Four exedrae, or blind tribunes, adorn the base of the drum.
19th century intervention – consisting primarily of new choir lofts and the simplification of Bandinelli's choir, from which the entire columned superstructure and the statues on the altar were removed – completed the decoration of the cathedral. But the most important operation of all was the construction of a new façade by Emilio De Fabris and his assistants between 1871 and 1884 in imitation of the decorative Florentine style of the 14th century that we find on the bell tower and the side doors of the cathedral.