The two most famous mosaics in San Vitale are definitely slightly younger and must date after 540, when the Byzantines had re-conquered Ravenna for the (Eastern) Roman Empire. These mosaics are political statements showing Emperor Justinian I (the Great) and his wife Theodora as rulers of Ravenna. (Justinian never actually visited Ravenna.)
The Justinian Mosaic is low on the northern apse sidewall. It shows Justinian I, emperor of the (East) Roman Empire, clad in imperial purple with a saint-like halo.
He is surrounded by court officials and church leaders, of whom Bishop Maximianus was the only one to manage working his name into the mosaic.
On the southern apse sidewall is the Theodora Mosaic. Here, the bejeweled wife of the emperor also has a saintβs halo and is followed by court ladies.
The expensive Byzantine court clothes are reproduced in great detail. Theodora was highly controversial in her time, as she was one of the most powerful women during the whole Roman era.