The decoration of the Early Christian churches was mostly with mosaics. The late 4th-century apse mosaic of Santa Pudenziana is the most hieratically explicit, and clearly didactic.
On the apse, Christ, depicted as teacher and lawgiver, although also enthroned in majesty as judge, is seated in front of a hill, representing Golgotha, with a jewelled cross rising from it. On either side of Christ are the Apostles, with St Paul on his right, the position of honour, and St Peter on his left. Behind them are two female figures, representing 'Ecclesia ex gentibus' and 'Ecclesia ex circumcisione'.
| Early Christian Mosaics |
| Early Christian Mosaics (all) |
| Mosaics in Rome |
| Santa Costanza | Santa Pudenziana | Santa Maria Maggiore |
| Santi Cosma e Damiano | Other churches |
| Mosaics in Ravenna |
| Galla Placidia | Orthodox and Arian Baptisteries | San Vitale |
| Sant'Apollinare in Classe | Sant'Apollinare Nuovo |
| Mosaics in other places |
