Traditio Clavium Mosaic
Mosaic in the main niche in the south ambulatory, dating from either the 5th or the 7th century. It has been poorly restored, but its richly decorated border reveals the quality of the original. The mosaic depicts the Traditio Clavium, in which Christ hands over the keys to the kingdom of heaven to St. Peter (Matthew 16:9). Christ is shown with a beard and seated on a globe as Pantocrator.