The Age of Justinian I (527–565)

The nearly forty-year reign of Emperor Justinian I (527–65) heralded extensive territorial expansion and military success for the Byzantine state. Seeking to recover regions lost to foreign invaders, particularly Germanic tribes in Italy and North Africa, Justinian launched one of the most aggressive military programs in medieval history. As a result of his reconquest of the western territories, he restored Ravenna's status as a capital in Italy. Mosaic portraits of Justinian and his empress Theodora appear there at the church of San Vitale. By his death in 565, the empire bordered nearly the entire Mediterranean Sea, a size unrivalled in Byzantine history from that point onward. Conquest and territorial reorganization were paralleled by reforms in state taxation and legislation, the latter codified in the Corpus Juris Civilis (Corpus of Civil Law), a text that today forms part of the foundation of the Western legal system.

Justinian's reign is further distinguished by an exceptional record of architectural and artistic production. The rebuilding of Hagia Sophia (Church of Holy Wisdom) in Constantinople from 532 to 537 was the paramount achievement of Justinian's building campaigns. As the most important church during the empire's long history, Hagia Sophia set a standard in monumental building and domed architecture that would have a lasting effect on the history of Byzantine architecture. In addition to the cathedral of Hagia Sophia, Justinian patronized over thirty churches in the capital of Constantinople and both ecclesiastical and secular building throughout the empire's territories, even as far as Mount Sinai in Egypt. During his reign, silk production was introduced from China, an art form for which Byzantium would soon become famous throughout the medieval world.