Survival of the Eastern Roman Empire

Introduction

While the Western Roman Empire collapsed in the fifth century, the Eastern Roman Empire, ruled from Constantinople, survived. The eastern state retained control of the Balkans, the eastern Mediterranean, Egypt, and much of Asia Minor, and it would continue, in various forms, for nearly another thousand years, until the fall of Constantinople to the Ottoman Turks in 1453. Modern historians call this state the Byzantine Empire, but it is important to remember that its inhabitants always called it Romania, the Roman Empire, and considered themselves to be Romans.

This article surveys the reasons for the eastern Empire’s survival, the major events of the fifth and sixth centuries, the great reign of Justinian, and the long aftermath of the western Empire’s fall. For the broader context, see the The Fall of the Western Roman Empire. For the later history of the eastern Empire, see the The Byzantine Empire.

Why the East Survived

The eastern Empire was not simply luckier than the west. It was structurally stronger in several important ways. First, it was wealthier. The eastern provinces, especially Egypt, Syria, and Asia Minor, were the richest in the Mediterranean. The annual grain harvest from Egypt alone could feed the city of Constantinople and much of the eastern Empire. Second, the eastern Empire was more urbanized. Cities like Constantinople, Antioch, Alexandria, and Ephesus were major centers of population, trade, and culture, and they remained so throughout the early Middle Ages. Third, the eastern Empire had a stronger tax system and a more professional bureaucracy, which allowed it to extract resources from its population and use them to fund a large and effective army.

A fourth factor was geography. Constantinople itself was nearly impregnable. Surrounded on three sides by water and protected on the fourth by the famous Theodosian Walls, the city was difficult to capture by any pre-modern army. The eastern Empire’s other major cities, Antioch, Alexandria, and Jerusalem, were similarly defensible. By contrast, the western Empire’s capital, Ravenna, was in the middle of difficult terrain and could not project power as easily.

A fifth factor was the eastern Empire’s diplomatic skill. The eastern emperors were masters of the diplomatic art, using a combination of threats, bribes, marriage alliances, and religious appeals to manage relations with the Sassanid Persians, the Huns, the Germanic kingdoms, and the steppe peoples. The eastern Empire’s diplomacy often succeeded where the western Empire’s brute force failed.

A sixth factor, harder to measure but no less important, was the depth of classical and Christian culture in the eastern cities. Constantinople was, by the fifth century, the largest city in the Mediterranean, with perhaps half a million inhabitants, a sophisticated school system, libraries, and a thriving intellectual life. The eastern provinces had deep roots in classical Greek culture, and they were the home of the great Christian theologians of the fourth and fifth centuries, including the Cappadocian Fathers and John Chrysostom. This dense cultural infrastructure gave the eastern Empire a degree of cohesion that the western provinces, more recently Romanized, often lacked.

Theodosius II and the Defense of the East (408–450)

The early fifth century was a difficult time for the eastern Empire. Theodosius II, who ruled from 408 to 450, was a quiet and studious emperor who left much of the actual government to his older sister, Pulcheria, and to his wife, Eudocia. Theodosius’s reign saw the construction of the famous Theodosian Walls of Constantinople, completed in 413, which would protect the city for the next thousand years. He also established the University of Constantinople, a major center of classical learning.

Theodosius’s reign also saw the eastern Empire’s increasing withdrawal from the west. He supported the usurper Joannes against Honorius in 423–425, then abandoned him to be defeated. He imposed Valentinian III as western emperor in 425, effectively subordinating the western government to the eastern court. As the western Empire declined, the eastern Empire tried to keep it alive, but with diminishing commitment and resources.

The Reign of Zeno and the Loss of the West (474–491)

The emperor Zeno (r. 474–491) was a colorless Isaurian chieftain whose chief importance lies in the fact that he ruled the eastern Empire when the western Empire ended. In 476, Odoacer deposed Romulus Augustulus and sent the imperial regalia to Constantinople. Zeno, after some hesitation, recognized Odoacer as king of Italy, and the western emperorship was at an end.

Zeno’s most consequential decision was to encourage the Ostrogothic king Theodoric to invade Italy. Theodoric, who had been a hostage at Constantinople and a major figure in the Balkans, was given the title of magister militum and sent against Odoacer. Theodoric invaded in 488, defeated Odoacer in 493, and established the Ostrogothic kingdom in Italy. Although this kingdom was, in form, subordinate to the eastern Empire, it was in practice an independent state. The west had been lost, but the eastern Empire had regained a foothold in Italy.

Anastasius and the Long Peace (491–518)

The emperor Anastasius I (r. 491–518) was a man of humble origins from Dyrrhachium, who married the widow of Zeno. His reign was long and eventful. He reformed the tax system, abolished the chrysargyron, a heavy tax on traders that had been very unpopular, and presided over a long period of peace with the Sassanid Persians.

The peace with Persia allowed Anastasius to focus on the Balkans, where he fortified the major cities and built a new defensive line, the Anastasian Wall, across the Thracian plain. He also faced serious religious unrest at home, including riots in Constantinople against his Monophysite sympathies. Anastasius was, like many late Roman emperors, more interested in religious than in military affairs, and his reign saw a further weakening of the western position.

Justinian and the Reconquest of the West (527–565)

The reign of Justinian I (r. 527–565) is one of the most important in Roman history. Justinian, a Thracian of peasant origin, came to the throne with a vision of restoring the Roman Empire to its ancient boundaries. He was one of the most able administrators, legislators, and builders in Roman history, and he was supported by his wife, the empress Theodora, and by some of the most capable generals of the age, including Belisarius and Narses.

Justinian’s reign saw the codification of Roman law in the famous Corpus Juris Civilis, the construction of the great church of Hagia Sophia in Constantinople, and ambitious military campaigns in the west. In 533–534, Belisarius destroyed the Vandal kingdom in Africa and recovered the wealthy African provinces for the Empire. In 535–540, Belisarius and later Narses conquered the Ostrogothic kingdom in Italy, after a long and devastating war. In 552, Narses defeated the Ostrogoths decisively at the Battle of Taginae, and the Ostrogothic kingdom was at an end.

Justinian’s reconquest of the West was, in some respects, the last gasp of the Roman Empire. By the time of his death in 565, the Empire controlled Italy, North Africa, parts of Spain, the Balkans, Asia Minor, and the eastern Mediterranean. But the reconquest had been enormously expensive, and the Empire’s resources were stretched thin. Within a few years, much of what Justinian had gained would be lost: the Lombards invaded Italy in 568, the Slavs settled the Balkans, and the Avars threatened the frontier. The reconquest had, in the long run, exhausted the Empire rather than revived it.

The Aftermath of Justinian

The century after Justinian’s death was a difficult one for the eastern Empire. The plague of 541 devastated the population. The Sassanid emperor Khosrow II invaded in 602, and for the next twenty-five years, the Empire fought for its very survival. The emperor Heraclius (r. 610–641) eventually defeated the Persians, but his victories were soon overshadowed by the rapid expansion of Islam in the 630s and 640s. Egypt, Syria, and North Africa were lost within a generation.

The eastern Empire survived these crises, but it was a much smaller and more compact state than it had been in the age of Justinian. It became, in effect, a Greek-speaking, Orthodox Christian state centered on Constantinople, the Balkans, and parts of Asia Minor. This state would survive, in various forms, until 1453. The story of its long history is taken up in the The Byzantine Empire.

The Roman Identity of the East

Throughout its long history, the eastern Empire remained Roman in its own eyes. The emperors styled themselves Basileus ton Rhomaion, “Emperor of the Romans,” and they claimed to be the legitimate successors of Augustus, Diocletian, and Constantine. The people of the Empire called themselves Rhomaioi, Romans, and this name persisted in many languages long after the Empire itself had ended. The modern Greek word for a Greek person, Romios, is a survival of this Roman self-identification.

The Roman identity of the eastern Empire had important consequences for the early Middle Ages. The eastern Empire saw itself as the legitimate Roman state, and it actively intervened in the religious, political, and military affairs of the west. It tried to reconquer the west under Justinian. It sent missionaries to the Slavs. It competed with the western Latin church for authority over the Christian world, a competition that would eventually produce the Great Schism of 1054. And it served as a model and a counterpoint to the new western political order, the kingdoms of the Franks, the Visigoths, the Lombards, and the Anglo-Saxons.

Conclusion

The survival of the eastern Roman Empire is one of the most important and underappreciated facts of the early Middle Ages. While the west was fragmenting into Germanic kingdoms, the east remained a centralized bureaucratic monarchy, ruled from Constantinople, and projecting power across the Mediterranean. The eastern Empire’s survival was due to a combination of structural advantages, including greater wealth, a stronger tax system, more urbanized population, and excellent diplomacy. Its history after the fall of the west was a long, varied, and fascinating one, full of great triumphs and terrible disasters, and it shaped the religious, political, and cultural map of the medieval Mediterranean.