 During the 13th and 14th centuries, the cathedral was damaged twice by earthquakes, in 1267 and 1303.The 1267 earthquake caused significant delay in the construction of the nave.Archbishop Giovanni del Conte, oversaw the completion of the nave and the narthex until 1319 and that of the middle aisle, the buttresses of the chevet, the façade and a chapel/baptistery from 1319 to 1326.