Exterior view

The church was begun by Bishop Ecclesius (reg 521-32) and financed by Julianus Argentarius, who spent 26,000 solidi on its construction; work progressed under bishops Ursicinus (reg 534-36) and Victor (reg 538-45), and the church was consecrated in 547 by Bishop Maximian.

The church is a domed octagon with an ambulatory and a woman's gallery. Eight large piers support the squinches that support the dome. The circular central space is varied by the addition of seven galleried niches while the eighth arc becomes instead a rectangular choir ending in an apse. From the exterior the church structure looks rational as these structures rise to the central dome. A long but narrow narthex is at an angle to the main axis.

View the cross section and ground plan of the building.