On the right is a mosaic depicting the East Roman Emperor Justinian I, clad in Tyrian purple with a golden halo, standing next to court officials, Bishop Maximian, palatinae guards and deacons.
Milan has long been considered the most likely place of origin, which has been further strengthened after the insignia on the shields of the soldiers were identified as those of a unit of the Palatine Guards stationed in Milan in the late 4th century, when Milan was the usual residence of the Imperial court.
Next to the old kind of school, the Scholae Palatinae, established by Constantine the Great as a replacement to the Praetorian Guard, was the training center of the imperial palace guard.