 The work evokes the mosaics of the Byzantine and Norman churches found in Cefalù and Monreale in Sicily.The mosaic, in large part made by Francesco da Pisa, was brought to completion by Vincino da Pistoia with the Madonna on the left side (1320).Among the medieval works that avoided destruction during the fire of 1595 are the fresco of the Madonna with Child in the triumphal arch by the Pisan artist Maestro di San Torpè, as well as the cosmati pavement, work rarely found outside of Lazio.