Byzantine Empire

Nobody in Constantinople ever called the state Byzantine; the word is a coinage of sixteenth century scholarship. Its subjects called themselves Rhomaioi, Romans, and understood their empire as the same one Augustus had founded, now Christian and now Greek speaking. Constantine refounded the city of Byzantion as his capital in 330, and for eleven centuries it remained the seat of an emperor who claimed universal authority under God.

The emperor's place in the church was the central and unresolved question of Byzantine political theology. He convened the ecumenical councils, confirmed their canons, appointed and deposed patriarchs, legislated on heresy and processed inside the sanctuary at his coronation. He was not a priest and could not celebrate the liturgy, yet Gilbert Dagron's study of the imperial office shows how persistently Byzantine ceremonial reached for priestly imagery, and how the western label of caesaropapism flattens a relationship in which patriarchs excommunicated emperors and monks brought them down.

Justinian I, who reigned from 527 to 565, is the clearest case of the two powers in one hand. He legislated on the theology of the Trinity, closed the Athenian schools, forced the bishops of the empire to condemn texts he disliked, and rebuilt Hagia Sophia after the Nika riot, dedicating in 537 a domed church so large that no builder attempted its equal for nine hundred years.

The empire spent much of the eighth and ninth centuries at war with itself over images. Emperors from Leo III moved against the veneration of icons; the Second Council of Nicaea restored it in 787; a second iconoclast period followed from 815 until the restoration of 843, still kept as the Sunday of the Triumph of Orthodoxy. Leslie Brubaker and John Haldon's reassessment argues that the destruction was far less systematic than the victorious iconophile sources claimed, and that the crisis was as much about imperial authority as about theology. Its settlement gave Orthodoxy a theology of the image that has governed its art ever since.

Outward, the empire's greatest export was its religion. The mission of Cyril and Methodius in the 860s produced a Slavonic alphabet and liturgy, and the conversion of Rus at Kiev around 988 carried Byzantine Christianity into the lands that became Russia, Ukraine and Belarus.

The breaks came in turn. The mutual excommunications of 1054 hardened the estrangement from Rome into schism; the Fourth Crusade sacked Constantinople in 1204 and ruled it for fifty seven years, an injury that made reunion politically impossible; and on 29 May 1453 the city fell to Mehmed II, who converted Hagia Sophia into a mosque. What survived was the church: autocephalous Orthodox patriarchates, a liturgy, and in Moscow the claim to be a third Rome.