Justinian I (ca. 482-565) was Byzantine emperor from 527 to 565. Ruling in a transitional epoch, he was both a conscious steward of the past and a pragmatic innovator.

The Roman Empire in the 4th century was an all-Mediterranean Christian state with an Eastern focus. But in the 5th century it was shattered by internal dissensions and eroded by barbarian attacks. Various Germanic tribes dismantled the Western provinces and established their own regional kingdoms, such as those of the Visigoths in Spain, the Vandals in North Africa, the Franks in Gaul, and the Ostrogoths in Italy. As recognized upholders of the continuing Roman imperial tradition, the Eastern line of emperors in Constantinople survived barbarian dangers, thanks to the richer resources of the Eastern provinces. But they faced internal strife, regional unrest, and sectarian religious controversy in these provinces. Subsequent developments in the 7th century would make the Eastern provinces into...