The portal is probably from the early 12th century. On its side are the figures of the Four Major Prophets, each bearing a roll with the text of their prophecies. The narthex was made by masters from Campione in the following century: it incorporates an older frieze portraying the Labours of the Months (late 12th century, inspired by that in the Baptistery of Parma). The four statues on the upper loggia, portraying the "Madonna with Child" and two bishops, are of the Tuscan school (1310). The columns of the narthex stand on two lions in Verona marble. The left one is holding a dragon, symbol of Evil, in his paws, while the right one is holding a bear, which in turn is biting a bird's neck.