Nobody in this chapter called themselves Byzantine. The word was coined by a German scholar in the sixteenth century and became standard much later.
They called themselves Romans. Their state was the Roman Empire, their emperor was the Roman emperor, their law was Roman law, and when the Arabs and the Persians and the Turks referred to them they used a version of the same word. That they spoke Greek did not strike them as a contradiction, any more than speaking Latin had made a Spaniard less Roman four centuries earlier.
The renaming matters because it encodes a judgement. Calling them Byzantines lets the story of Rome end tidily in the west in 476, and lets a separate, exotic, faintly disreputable thing carry on in the east. Western writers from the eighteenth century onwards used the word as a synonym for palace intrigue and pointless theological hair splitting, and a good deal of that stuck.
What actually carried on was the continuous Roman state, with an unbroken succession of emperors and law courts, for a period longer than the gap between it and us.
Four reasons, and none of them is virtue.
It was richer. Egypt, Syria and Asia Minor were the productive provinces of the ancient Mediterranean, with dense populations, large cities and an agricultural surplus that the western provinces could not match. A state that can tax that can pay an army.
Its frontier was shorter and its enemy was a state. The west had to defend the Rhine and the Danube against many groups arriving at unpredictable points. The east faced Persia, which was a rival empire with a capital, a diplomatic service and an interest in stable borders. You can make treaties with a Persia. You cannot make one treaty with a migration.
It had a capital that could not be taken. Constantinople sits on a peninsula with water on two sides, a superb harbour, and a single land approach. In 413 that approach was closed with a triple line of walls, ditch, outer wall, and an inner wall twelve metres high, which was the most formidable fortification in the world and was not breached by an enemy for over eight hundred years.
And it kept its money and its offices. Gold coinage of stable weight, struck from Constantine’s reform onwards, circulated for centuries and was accepted from Britain to India. A bureaucracy that recruited by literacy and examination outlived individual emperors. When an emperor was murdered, which happened often, the tax registers were still there in the morning.
In the sixth century one emperor tried to undo the loss of the west, and his reign is the best illustration of both what the state could do and what it could not afford.
Justinian reconquered North Africa quickly and Italy slowly and catastrophically, in a war that lasted twenty years and left the peninsula more damaged than the previous century of Gothic rule. He built the great domed church of Holy Wisdom in Constantinople, which stood as the largest enclosed space in the world for something like a thousand years and is still standing. He put down a riot in the capital that nearly removed him, by having the crowd penned into the racecourse and killed, and the figure the sources give for the dead runs to tens of thousands.
And he ordered the codification of Roman law. A commission gathered the entire mass of imperial legislation and the accumulated opinions of the jurists, cut the contradictions, and issued the result as the authoritative text. That compilation is the single most consequential thing in this chapter, because it is the form in which Roman law survived, and it is the text that western Europe rediscovered in the eleventh century and built its own legal systems on.
Then in 541 a plague arrived, almost certainly bubonic, which we can now confirm from ancient bacterial DNA recovered from burials. It killed a large but genuinely unknown share of the population, returned in waves for two centuries, and gutted the tax base at exactly the moment the reconquest needed paying for. Most of what Justinian had retaken was lost within a generation of his death.
The lesson the state drew was defensive, and it drew it correctly. For most of the next eight hundred years it did not try to restore the empire. It tried to survive, and it developed an entire diplomatic culture around doing so with bribes, marriages, hired allies and delay rather than battles.
The seventh century is the hinge. In about eighty years the empire lost more than half of everything.
It began with a war against Persia so exhausting that both empires spent their reserves and their manpower. The Persians took Syria, Egypt and Jerusalem; the Romans clawed them back in a brilliant campaign; and then, with both sides ruined, Arab armies carrying a new religion arrived out of the south.
Within twenty years Syria, Palestine, Egypt and eventually North Africa were gone permanently. These were the richest provinces, the ones the previous section named as the reason the east survived, and they were also full of Christians whose theology the capital had spent two centuries condemning, which is part of why the conquest met so little local resistance.
What was left was Asia Minor, the Balkans, and the city. The state reorganised around it. Provincial administration was replaced by military districts where soldiers held land in return for service, which is cheaper than paying them. Latin, which had still been the official language of the law, gave way to Greek. Twice, in 674 and 717, Arab armies and fleets besieged Constantinople, and twice the walls, the navy and a chemical incendiary the Romans kept as a state secret held them off.
It is worth stating plainly what that meant for everyone west of it. For four centuries the empire absorbed the main force of expansion from the east, and the kingdoms of western Europe grew up behind that shield without knowing they were behind anything.
The empire that emerged was smaller, tougher and more military, and it went on for another five hundred years, with a serious recovery in the tenth and early eleventh centuries when it pushed back into Syria and the Balkans.
Two of its exports outlasted it. The first is Orthodox Christianity, carried north by missionaries into the Slavic world. Two brothers from Thessalonica devised an alphabet to translate scripture into Slavonic, and the writing systems used today in Russia, Ukraine, Bulgaria, Serbia and elsewhere descend from that work. When the ruler of the Rus chose a religion in the late tenth century, he chose this one, and the cultural border that decision drew across eastern Europe is still visible in almost any map of religion, alphabet or architecture.
The second is the texts. Constantinople copied, taught and argued over the Greek classics continuously. Plato, Aristotle, Euclid, Ptolemy, Galen, the tragedians and the historians came through in Greek because scribes in that empire kept making copies. Much of it reached the Latin west twice over: first through Arabic translations made in the Islamic world, and then directly, in Greek, carried by scholars leaving a shrinking empire in the fourteenth and fifteenth centuries.
The recovery had a specific and unglamorous basis. A run of competent soldier emperors in the tenth century inherited a frontier organised around small landholding cavalrymen, an enemy world in Syria and Mesopotamia that had fragmented into rival emirates, and a treasury that had been left alone. They pushed the border east and south, retook Crete and Antioch, and broke the Bulgarian state in the Balkans after a war of thirty years. Within fifty years of that high point the frontier collapsed again, after a defeat in eastern Anatolia in 1071 that mattered less for the battle than for the civil war the losers fought afterwards, which let Turkish groups settle the interior unopposed.
The blow it did not recover from came from fellow Christians. In 1204 a crusading army that had run out of money was diverted, by a mixture of Venetian commercial interest and a disputed imperial succession, into attacking Constantinople. It took the city, sacked it for three days, melted the bronze, stole the relics, and installed a Latin emperor. The Greeks recovered the city in 1261 but never the strength, and the horses that stand on the front of the basilica in Venice were taken in that raid.
The reputation for interminable theological dispute is not unfair, but it is usually reported without the point.
The controversies were about how a divine and a human nature could exist in one person, and about whether images of Christ and the saints could be venerated without idolatry. The second question, which convulsed the empire for over a century, produced organised destruction of images and then their restoration, and it is remembered in the word iconoclasm.
These look like abstractions and they were not. In a state where the emperor’s authority was religious as well as political, a ruling on doctrine was a ruling on who was inside the community, and the losing side of each dispute became a population with a grievance. The alienation of the Syrian and Egyptian churches by the councils of the fifth century is the clearest case: it left the empire’s richest provinces full of people who did not much mind who governed them.
The same argument, running west, eventually split Christianity in two. Disputes over the pope’s authority, over a clause added to the creed in the west, and over practice and language accumulated for centuries, and the mutual excommunications of 1054 are conventionally taken as the break. Like 476, the date is a marker chosen afterwards for a process that took much longer, and the sack of 1204 did more to make the division permanent than any document.
Firm: this is a well documented state. It has archives, law codes, chronicles, saints’ lives, seals, coins and a large surviving architecture. We know its administrative structures in detail.
Soft: the seventh century. It is the worst documented stretch, precisely because it was the worst stretch, and our narrative sources for the Arab conquests were written later on both sides with religious framings.
Soft: the plague. That it was bubonic is now established from DNA. How many it killed is not. Estimates in print range from a modest regional die off to a third or more of the empire, and the argument turns on how much weight to give ancient writers who were not counting.
Contested: whether the empire deserves the reputation for stagnation. The older western judgement, of a thousand years of decline and ceremony, has been largely dismantled by specialists, who point to periods of real military recovery, economic growth and intellectual work. But the field also has a tendency to overcorrect, and it is fair to say the state was structurally conservative and repeatedly chose stability over change.
A framing worth resisting: the idea that this empire was holding the line for Europe. It was defending itself. That western Europe benefited was a side effect, and the west repaid it in 1204.