History of the Byzantine Empire

The Byzantine Empire was one of the longest-lasting civilizations in human history, surviving for over a thousand years in a region that today forms the heart of modern Turkey, Greece, and the Balkans. At its peak, it was the most powerful economic, cultural, and military force in Europe, preserving the legal, intellectual, and artistic heritage of the Roman world while developing its own distinct identity rooted in Orthodox Christianity, Greek language, and Roman political tradition.

This overview traces the full arc of Byzantine history, from the moment Emperor Constantine the Great refounded Byzantium as Constantinople in 330 AD, through the great dynasty of Justinian, the trauma of Iconoclasm, the brilliant revival of the Macedonian Dynasty, the catastrophic Fourth Crusade, and the slow decline that ended when Ottoman cannons breached the walls of Constantinople on 29 May 1453.

The Origins: From Rome to the New Rome

Constantine and the Foundation of Constantinople (306–337 AD)

The story of Byzantium begins with a Roman emperor. Constantine I, known as Constantine the Great, ruled the Roman Empire at a moment of profound crisis. After years of civil war and persecution of Christians, he sought a new capital that would anchor the eastern half of the empire. In 330 AD, he dedicated the city of Constantinople on the site of the ancient Greek colony of Byzantion.

The choice was strategic. Constantinople sat at the crossroads of Europe and Asia, controlling the Bosphorus straits that link the Black Sea to the Mediterranean. It could be supplied by sea and protected by formidable land walls. Constantine populated his new capital with citizens drawn from across the empire, endowed it with the great church of Hagia Eirene, and granted it the title “New Rome.” Within decades, the city would also become the seat of Christian imperial authority, especially after the dedication of the original Hagia Sophia by his son Constantius II.

Constantine’s conversion to Christianity, proclaimed by the later tradition in his vision at the Milvian Bridge in 312, transformed not only the empire but the course of Western civilization. From this point forward, church and state would be intertwined in Byzantine political thought in a way that had no parallel in the Latin West.

The Late Roman Empire (337–518 AD)

For nearly two centuries after Constantine, the Roman Empire continued to function as a single, if increasingly divided, state. Emperors like Theodosius I, who in 380 AD made Nicene Christianity the official religion of the empire, ruled from Constantinople or Milan. The administrative division between Eastern and Western halves became formal in 395 AD, when Theodosius bequeathed the empire to his two sons.

The fifth century was catastrophic for the Western Roman Empire. Germanic tribes, the Huns, and internal decay brought the western line of emperors to an end in 476 AD. The Eastern Empire, meanwhile, survived. Defended by the formidable walls of Constantinople, by Greek fire, and by a sophisticated diplomacy that played rivals against each other, the eastern state endured. Justinian would later boast that the empire knew no boundaries, but in practice, the Eastern Empire was becoming a Greek-speaking, Orthodox Christian civilization increasingly distinct from the Latin West.

The Age of Justinian (518–602 AD)

Justinian I and the Restoration of Roman Power

The single most important reign in Byzantine history began in 527 AD, when Justinian I ascended the throne. Justinian was a Latin-speaking peasant from Illyricum who had been adopted by his uncle, the emperor Justin I. He was also one of the most ambitious rulers in world history. His goal was nothing less than the restoration of the entire Roman Empire, and he came closer to achieving it than any ruler after Theodosius.

Justinian’s military generals, including the brilliant Belisarius and the eunuch Narses, reconquered North Africa from the Vandals, Italy from the Ostrogoths, and parts of southern Spain from the Visigoths. The Vandalic War (533–534) and the Gothic War (535–554) doubled the size of the empire and restored Mediterranean unity. These campaigns also produced the legend of Empress Theodora, Justinian’s wife, who reportedly saved his throne during the Nika Riots of 532 by refusing to flee and exhorting him to act with resolve.

Law, Architecture, and Faith

Beyond the battlefield, Justinian’s legacy is most clearly visible in three areas. First, the Justinian Code, compiled under the direction of the jurist Tribonian, became the foundation of civil law across Europe and remains influential today. Second, the rebuilding of the Hagia Sophia after the Nika Revolt produced what was, for a thousand years, the largest cathedral in the world. Third, the doctrinal work of the Fifth and Sixth Ecumenical Councils, held in Constantinople, defined orthodox Christianity against Monophysite and Monothelite heresies.

Yet the cost of this greatness was severe. The wars of reconquest exhausted the treasury, the population, and the army. By the time of Justinian’s death in 565, the empire was overextended, and within a generation much of Italy had been lost to the Lombards.

Crisis and Transformation (602–717 AD)

The Sassanid Threat and the Loss of the East

The seventh century was, in many ways, the nadir of Byzantine history. The Sassanid Persians under Khosrow II invaded the empire, capturing Jerusalem in 614 and sacking it, and even briefly threatening Constantinople itself. The emperor Heraclius, who came to power in 610, mounted one of the most remarkable military campaigns in history, marching his army deep into Persian territory and ultimately forcing a peace that returned the True Cross to Jerusalem in 628.

Heraclius had little time to celebrate. Within just a few years, a new and even more dangerous enemy appeared on the southern frontier: the armies of Islam. At the Battle of Yarmouk in 636, the Byzantines suffered a catastrophic defeat that lost them Syria, Palestine, and Egypt, the empire’s richest grain-producing provinces. Within a century, the Byzantines would also lose North Africa to the Arabs.

The Defensive Triumph of the Isaurian Dynasty

The Isaurian dynasty, founded by Leo III in 717, transformed the empire from a Mediterranean power into a defensive Greek-speaking state. The new strategic innovation was the theme system, a militarized administrative structure that bound soldier-farmers to specific provinces in exchange for land grants. This system produced a formidable defensive army and helped Byzantium survive the second great Arab siege of Constantinople in 717–718, which proved to be the high-water mark of the Umayyad Caliphate.

The Isaurians also initiated the great religious controversy of Byzantine Iconoclasm, a debate over the veneration of religious images that divided the empire for more than a century. Beginning in 726 and lasting in two phases until 843, Iconoclasm was at once a theological dispute, a political assertion of imperial authority over the church, and, some historians argue, an attempt to align Byzantine practice with the iconoclastic sensibilities of Islam and Judaism.

The Macedonian Renaissance (867–1056)

The Rise of the Macedonian Dynasty

The accession of Basil I, a peasant from Macedonia who murdered his way to the throne, inaugurated the most brilliant and stable period in Byzantine history. The Macedonian Dynasty, which ruled from 867 to 1056, presided over a true renaissance in art, literature, law, and military power.

Under rulers like Leo VI the Wise, Constantine VII Porphyrogennetos, and Basil II the Bulgar-Slayer, the empire reached a level of cultural achievement comparable to the Italian Renaissance seven centuries later. Constantine VII’s works on imperial ceremony, military tactics, and diplomacy were read and copied for centuries. The Macedonian era also saw the conversion of the Slavs, the Bulgarians, and the Serbs to Orthodox Christianity, extending Byzantine cultural influence deep into Eastern Europe.

Basil II, who reigned from 976 to 1025, was the greatest military emperor since Justinian. He smashed the Bulgarian Empire at the Battle of Kleidion in 1014, allegedly blinding 15,000 prisoners and leaving one in every hundred with one eye to lead the rest home. He annexed Bulgaria, expanded into Armenia and Georgia, and at his death ruled an empire that stretched from southern Italy to the Caucasus and from the Danube to Syria.

The Crisis of the Eleventh Century (1025–1081)

The Macedonian achievement was squandered within a generation. Basil II left no capable heir, and the dynasty collapsed into a series of weak, often short-lived rulers dominated by court eunuchs and aristocratic families. The great military families of Anatolia, neglected by the central government, began to build up private power bases that would eventually evolve into Turkish beyliks.

The catastrophe came in 1071, when the Seljuk Turkish sultan Alp Arslan crushed the Byzantine army at the Battle of Manzikert in eastern Anatolia. Within a decade, most of Anatolia, the empire’s recruiting ground and economic heartland, was lost to Turkish control. Although the Byzantines would hold cities and coastal regions in Anatolia for centuries, they would never again control the interior plateau.

The disaster of Manzikert coincided with, and in part caused, the religious schism with the Latin West known as the Great Schism of 1054, which divided Christianity into its Orthodox and Catholic branches. The two events were not unrelated: the emperor’s request for military aid from the Pope in exchange for reuniting the churches set the stage for the Crusades.

The Comnenian Restoration and the Crusades (1081–1204)

The Comnenian dynasty, beginning with Alexios I in 1081, partially restored Byzantine fortunes. Alexios was a brilliant diplomat and general who used Western Crusader armies, originally summoned to help against the Seljuks, as mercenaries in his campaigns against the Seljuk and Pecheneg enemies in Asia Minor and the Balkans. The relationship with the Crusaders was, however, always tense. Western and Greek Christians had grown apart in language, ritual, and political culture, and the Comneni struggled to control the unruly Crusader armies passing through their territory.

The Crusades, intended to help Byzantium, ultimately destroyed it. The Fourth Crusade, diverted from its original objective of attacking Egypt, was instead directed at Constantinople itself by the scheming prince Alexios IV Angelos and the doge of Venice, Enrico Dandolo. In 1204, the Crusaders sacked Constantinople, an event of such trauma that modern Greeks still refer to it simply as “the Catastrophe.” The city was subjected to three days of pillage, its libraries burned, its churches desecrated, and its population reduced from perhaps half a million to fifty thousand.

The Empire in Exile and the Palaiologan Twilight (1204–1453)

The States of the Dispersion

After 1204, Byzantine power survived in three successor states: the Empire of Nicaea in western Asia Minor, the Despotate of Epirus in northwestern Greece, and a small Latin Empire in Constantinople itself. The ruler most responsible for the restoration was Michael VIII Palaiologos, who in 1261 recaptured Constantinople in a daring nighttime assault.

The restored Palaiologan empire was, however, a shadow of its former self. It controlled little more than Constantinople, parts of Thrace and Macedonia, and a few Aegean islands. Surrounded by the restored Bulgarian Empire, the Serbian Empire of Stefan Dušan, and the rising Ottoman Turkish state in Anatolia, the Byzantines played a desperate game of diplomatic and military survival.

The Final Century

The last Byzantine emperor, Constantine XI Palaiologos Dragases, came to the throne in 1449, ruling a state that consisted essentially of the city of Constantinople and a thin strip of land around it. On 6 April 1453, the Ottoman sultan Mehmed II laid siege to the city with an army estimated at 80,000 men and a fleet of over 100 ships. The siege lasted 53 days. On 29 May 1453, after the famous giant cannon built by the engineer Orban had finally breached the Theodosian walls, Ottoman troops poured into the city. Constantine XI, according to tradition, charged into the breach and died fighting. The last Roman emperor fell, and with him, the empire he represented.

The fall of Constantinople sent shockwaves across the Christian world. In Rome, bells tolled. In Russia, the Grand Duke of Moscow began to claim the mantle of the third Rome, the inheritor of Byzantine imperial and religious tradition. Greek scholars fleeing west would help spark the Italian Renaissance. The Ottoman Empire, now anchored in Europe, would dominate the eastern Mediterranean for the next four centuries.

Themes and Patterns in Byzantine History

Several patterns emerge from this thousand-year survey. First, the Byzantine state was remarkably resilient, capable of recovering from disasters that would have destroyed lesser polities. Manzikert, the loss of Anatolia, the Fourth Crusade, the Black Death, and the final Ottoman onslaught all seemed fatal, yet the empire persisted.

Second, the relationship between church and state was central. Unlike the Latin West, where popes and emperors contested power, in Byzantium the emperor claimed authority over the church, which both unified the state and created repeated conflicts with those who resisted imperial interference in doctrine, especially during Iconoclasm and the monastic hesychast controversy.

Third, Byzantine diplomacy was as important as Byzantine arms. Emperors skillfully played nomadic steppe peoples, Western powers, and Islamic caliphates against one another, preserving Byzantine independence long after the empire’s military strength had declined.

Fourth, Byzantine art, architecture, and religion preserved and transmitted classical learning, Christian theology, and Hellenistic aesthetic principles across centuries, directly shaping the Byzantine legacy in modern Greece, Russia and Eastern Europe, and the Italian Renaissance.

Notable Byzantine Emperors

A complete study of Byzantine emperors reveals a remarkable range of personalities, from the saintly and devout to the monstrous and cruel. The list includes some of the most consequential rulers in world history:

• Constantine I (306–337): Founder of Constantinople and champion of Christianity.
• Justinian I (527–565): Restorer of Roman imperial power and codifier of Roman law.
• Heraclius (610–641): Defender of the empire against the Persians and innovator of Greek as the language of state.
• Leo III (717–741): Founder of the Isaurian dynasty and originator of Iconoclasm.
• Basil II (976–1025): The Bulgar-Slayer, the last great conquering Byzantine emperor.
• Alexios I Komnenos (1081–1118): Diplomat who summoned the First Crusade.
• Michael VIII Palaiologos (1259–1282): Recaptured Constantinople in 1261.
• Constantine XI Palaiologos (1449–1453): The last Byzantine emperor, who died defending his city.

Conclusion

The history of the Byzantine Empire is the history of a civilization that preserved the Roman tradition, developed Orthodox Christianity into a defining cultural force, and transmitted the artistic, legal, and intellectual heritage of antiquity to the modern world. Its thousand-year span encompasses military triumphs and disasters, theological controversies and artistic renaissances, and the slow, painful process of decline that ended only with the death of Constantine XI in the rubble of his breached capital.

To understand Byzantine history is to understand the foundation of modern Greece, the roots of Russian and Balkan civilization, the origins of much European law, and the long shadow that classical antiquity cast over the medieval and modern Mediterranean world. The study of Byzantium is not a footnote to the history of Rome: it is, in many ways, the continuation of that history, and its most enduring legacy is the world we live in today.

Related Articles

• The Reign of Justinian I — the dynasty that defined Byzantine law and ambition
• Byzantine Iconoclasm — the century-long war over holy images
• The Macedonian Dynasty — the golden age of Byzantium
• The Fall of Constantinople — the end of an empire
• Byzantine Emperors: A Study of Power — the men who ruled the state
• The Nika Riots of 532 AD — the revolt that nearly toppled Justinian
• The Battle of Manzikert — the disaster that lost Anatolia
• The Fourth Crusade and the Sack of Constantinople — the event that broke the empire
• Empress Theodora: Power Behind the Throne — the woman who saved an empire
• The Theme System: Byzantine Military Organization — the administrative innovation that saved Byzantium

Periodization and Historiography

The Periods of Byzantine History

Historians of Byzantium have long divided the history of the empire into a number of periods, each with its own character and its own significance. The earliest of the periods, the late antique period from 330 to 610, was the formative period of the empire, in which the institutions of the Roman state were adapted to the new Christian context and the foundations of the Byzantine civilization were laid. The middle period, from 610 to 867, was the period of crisis and recovery, in which the empire survived the catastrophic losses of the seventh century and gradually rebuilt its strength. The Macedonian period, from 867 to 1056, was the golden age of the empire, the period of its greatest medieval extent and its most brilliant cultural achievement. The Comnenian period, from 1081 to 1185, was a period of partial recovery after the disaster of Manzikert, marked by the alliance with the Crusaders and the brilliant literary culture of the imperial family. The Palaiologan period, from 1261 to 1453, was the final period of the empire, in which the Palaiologan dynasty presided over a remarkable cultural renaissance even as the empire shrank under Ottoman pressure.

This periodization is not the only possible one, and different historians have proposed different schemes. Some historians emphasize the continuity of the empire, treating the whole span from 330 to 1453 as a single, unified civilization. Others emphasize the discontinuities, treating the Macedonian and Palaiologan periods as separate civilizations, distinct from each other and from the early Byzantine period. The choice of periodization is, in part, a matter of perspective, and different scholars have adopted different approaches depending on their interests and their interpretations.

Major Historians and Their Works

The history of Byzantium has been written by many great historians, both Byzantine and modern. The most important of the Byzantine historians include Procopius of Caesarea, the historian of the age of Justinian, whose Wars, Buildings, and Secret History are major sources for the sixth century; Agathias, the historian of the sixth century, whose Histories continue the work of Procopius; Theophanes the Confessor, the historian of the eighth and ninth centuries, whose Chronicle is a major source for the early Byzantine period; Constantine VII Porphyrogennetos, the emperor-historian of the tenth century, whose De Thematibus, De Administrando Imperio, and De Ceremoniis are major sources for the Macedonian period; Michael Psellos, the great polymath of the eleventh century, whose Chronographia is a major source for the late Macedonian and early Comnenian period; Anna Comnene, the princess-historian of the twelfth century, whose Alexiad is a major source for the Comnenian period; and Niketas Choniates, the historian of the late twelfth and early thirteenth centuries, whose History is a major source for the period of the Fourth Crusade.

The most important of the modern historians of Byzantium include George Ostrogorsky, the great German historian of the twentieth century, whose History of the Byzantine State is the standard one-volume history in English; Alexander Vasiliev, the Russian-American historian whose History of the Byzantine Empire is another standard one-volume history; John Julius Norwich, the British popular historian whose three-volume A Short History of Byzantium is the most accessible introduction to the subject; and the many specialists in the various periods and aspects of Byzantine history, whose monographs have transformed the field in the last generation.

Byzantium in the Modern Imagination

The Western View

The Western view of Byzantium has long been shaped by the legacy of the Crusades and the polemic of the Western church against the Eastern. The Byzantines have often been portrayed in the Western tradition as decadent, treacherous, and corrupt, in contrast to the noble and chivalric West. The famous description of the Byzantines by the French historian of the Crusades, Steven Runciman, as a “decadent” civilization that had “no moral principles” is a typical example of the Western view.

This view has been extensively revised in the modern period, especially in the second half of the twentieth century, as the field of Byzantine studies has matured and as scholars have come to appreciate the sophistication and the importance of Byzantine civilization. The Byzantines are now recognized as the principal heirs of the Roman tradition, as the principal defenders of Christian Europe against the Islamic invasions, and as the principal transmitters of the classical Greek heritage to the modern world. The Western view of Byzantium is, in this sense, a major element of the modern reassessment of the medieval world.

The Eastern View

The Eastern view of Byzantium has been very different from the Western view. In the Orthodox world, the Byzantines have been celebrated as the defenders of the true faith, as the patrons of the arts and letters, and as the model of the Christian emperor. The Byzantine heritage is a central element of the national identities of Greece, Russia, and the other Orthodox nations, and it is invoked in a wide range of contexts, from politics to scholarship to art.

The most important center of the Eastern view of Byzantium has been Greece, where the Byzantine heritage has been a central element of the national identity since the War of Independence. The Greek state has built its cultural policy around the Byzantine heritage, and the Greek Orthodox Church has preserved the Byzantine liturgical and theological tradition. The Byzantine heritage is, in this sense, a major element of the Greek national identity, and it is one of the most powerful and most enduring expressions of the Byzantine legacy in the modern world.