Venetian and Tuscan craftsmen, Mosaics of the apse

According to an inscription in the cartouches at the corners, the mosaics of this very small apse, known as a ‘scarsella’, would have been created between 12 May 1225 and 1228, by a Franciscan friar named Jacopo; Vasari identified this personage as Jacopo Torriti, known as an author of mosaics in the basilicas of San Giovanni in Laterano and Santa Maria Maggiore in Rome. The works, however, were most likely later: the vault of the apse has been attributed to a master of the circle of Coppo di Marcovaldo, operating around 1260-1270, while the mosaics of the arch are by Tuscan (Florentine and Pisan) masters working around 1265-1275. Venetian masters also operated here, from the beginning of the 1300s.

The decoration places the Mystical Lamb in the centre, within a mystical wheel of angels and candelabra, and four prophets and four patriarchs standing in spaces between the spokes. The wheel is supported, in turn, by kneeling telamons on Corinthian columns. On the north and south sides, respectively, we see the Madonna and Child, and John the Baptist enthroned. Mary appears again on the intrados of the entrance arch, flanked by the apostles; below her, in the keystone position of the innermost cornice, John the Baptist is now flanked by the apostles and evangelists. Above both of these, on the outer band of the cornice, is the bust of Christ in arabesques of foliage. In this sacred place, the mosaics celebrated God, and with Him, the patron saints and intercessors of Florentines: the Madonna and Baptist. The positioning of the apostles and evangelists on the arch suggests another allegory: these are the supporters of the Church, its ‘pillars and arches’. The central wheel symbolises the moment of Creation taking place within space; the Mystical Lamb (immolated but alive), described in the Apocalypse, symbolises the slain but risen Christ. The themes of death and resurrection are also symbolically present in the rite of Baptism, celebrated in the basin below: death comes to sin (with the immersion in water), and Christ offers rebirth (re-emergence from the water).