San Vitale was commissioned by Ecclesius, bishop of Ravenna, in 526 and completed in 547, the year Byzantium briefly reclaimed Italy from the Ostrogoths. The basilica has an octagonal plan — unusual in the West, and modelled in part on the Church of Saints Sergius and Bacchus in Constantinople, which it followed by only a few decades.

The mosaics covering the apse and presbytery walls show Byzantine pictorial language at full maturity. The gold ground is not a background but a description of space itself: figures hover weightlessly in a luminous void. Two panels are especially celebrated, showing the Emperor Justinian and the Empress Theodora with their retinues. Justinian is depicted not as a courtier or cleric but as the unified representative of state and church — and on the Theodora panel the niche behind the empress's head confers something close to saintly status.

The faces are oriented toward an iconic gaze rather than individual portraiture: eyes large, mouths small, the contours of the body dissolving beneath the drapery. This is the central move of Byzantine aesthetics — material reality recedes, symbolic meaning advances. Roman realism ends here, and a new visual language is established, one art will carry for a thousand years in fresco, icon, and mosaic.

San Vitale was inscribed on the UNESCO World Heritage List in 1996; its mosaics can still be seen in their original positions, their colour scarcely faded after fifteen centuries.