Appearance
7.3 — Byzantium
Nobody who lived in the Byzantine Empire ever called it that. They called themselves Romaioi — Romans — and their state the Roman Empire, because that is what it was: the eastern half of the Roman state, in continuous existence, never conquered, never refounded.
The name "Byzantine" was invented in 1557 by a German scholar, a century after the empire fell, and it was popularised by Enlightenment writers who wanted to deny that this Greek-speaking Orthodox monarchy was Roman. Gibbon described its history as "a tedious and uniform tale of weakness and misery". The adjective "byzantine", meaning needlessly complicated and devious, comes from that hostility.
It lasted 1,123 years after the western empire ended. This chapter is about what it actually was.
Why the east survived and the west did not
Chapter 5.5 covered the western collapse. The eastern half faced the same pressures and came through, for specific reasons.
It was richer. Egypt, Syria and Anatolia were the empire's most productive provinces, with dense cities, high agricultural yields and long-established trade. The tax base was simply larger.
It had a shorter, more defensible frontier. The Danube and the eastern border with Persia, rather than the whole length of the Rhine and Danube plus Britain and North Africa.
And it had Constantinople.
The city's position is the whole strategic story. It sits on a peninsula with water on three sides, controlling the Bosphorus — the only sea route between the Black Sea and the Mediterranean, and a natural crossing point between Europe and Asia. The Golden Horn was a deep sheltered harbour closed by a chain across its mouth. Only the landward side needed defending, and that is where the walls ran.
Attila turned away from it. The Avars, the Persians, the Arabs twice, the Bulgars, the Rus and the Ottomans repeatedly failed against it. It fell twice: to a Christian crusading army in 1204 and to the Ottomans in 1453.
Justinian
Ruling 527–565, and the most consequential of the emperors.
The law. He commissioned the compilation of a thousand years of Roman law into the Corpus Juris Civilis — the Code of imperial legislation, the Digest of juristic opinion, the Institutes as a textbook, and the Novels of his own new laws. This is the single most important legal document in world history after the fact, because it was rediscovered in Italy in the eleventh century, taught in the new universities, and became the foundation of the legal systems of continental Europe, Latin America, Japan and much of Africa and Asia (Chapter 5.4).
Hagia Sophia, completed in 537 in about five years — extraordinarily fast for a building of that scale. Its dome, 31 metres across, sits on pendentives, curved triangular sections that transfer the load of a circular dome onto four square-set piers, which allows a dome over a square space. The dome is pierced by forty windows at its base, so it appears to float, and Procopius wrote that it seemed suspended by a golden chain from heaven. It was the largest cathedral in the world for nearly a thousand years.
The reconquest. His general Belisarius retook North Africa from the Vandals and Italy from the Ostrogoths. The Italian campaign took nearly twenty years and devastated the peninsula — Rome changed hands several times and its population collapsed — and most of the gains were lost within a generation to the Lombards. It is generally judged a strategic overreach that exhausted the treasury and the army.
And the plague. The Plague of Justinian, from 541, was the first recorded pandemic of Yersinia pestis — the same bacterium as the Black Death, confirmed by DNA recovered from sixth-century burials. Mortality estimates have been revised downward in recent scholarship and remain large. It recurred for two centuries. Combined with the volcanic cooling of 536 (Chapter 5.5), it broke the empire's demographic and fiscal capacity at exactly the moment of maximum extension.
The Nika riots of 532 are worth one line because of how they ended: rival chariot-racing factions united against the government, half the city burned, and Justinian was preparing to flee when his wife Theodora — a former actress, which in that period meant something close to a prostitute — told him that the imperial purple made a fine burial shroud. He stayed; the riots were suppressed with around 30,000 dead in the Hippodrome.
Surviving the seventh century
Between 602 and 718 the empire nearly ended.
The Persian war of 602–628 cost it Egypt, Syria and Jerusalem, and they were recovered only after Heraclius's remarkable counter-campaign. Then the Arab conquests took Syria, Egypt and North Africa permanently within a decade (Chapter 7.1) — the richest provinces, gone.
The Arabs besieged Constantinople twice, in the 670s and in 717–718, and failed both times. The second siege is one of the genuinely decisive events in European history — had the city fallen, there was nothing organised between there and the Danube.
Greek fire is part of why they failed: an incendiary liquid, projected through siphons from ships, that burned on water and could not be extinguished conventionally. Its composition was a state secret so well kept that it is still not known, though petroleum distillate with additives is the standard reconstruction.
And the state reorganised to survive. The theme system converted provinces into military districts where soldiers held land in exchange for service — turning a paid professional army the treasury could no longer afford into a self-supporting militia rooted in the land it defended. It worked for centuries.
Iconoclasm
From 726 to 843, with an interruption, the empire fought a bitter internal conflict over religious images.
The iconoclast position: images of Christ and the saints are idols, prohibited by the commandment, and their veneration is why God has allowed the empire to be defeated by the Arabs. The iconodule position: the incarnation means God took a visible form, so depicting him is legitimate, and veneration passes to the person depicted rather than resting on the image.
Icons were destroyed on a large scale, which is why very little Byzantine religious art from before this period survives, and monasteries — the main defenders of images — were persecuted.
The iconodules won in 843, and the restoration is still commemorated in Orthodox churches as the Triumph of Orthodoxy. The episode matters beyond art: it hardened the difference with Rome, which never accepted iconoclasm, and it is a rare case of a state attempting to change a population's religious practice by decree and failing over a century.
The split with Rome
The Great Schism is conventionally dated to 1054, when papal legates and the Patriarch of Constantinople excommunicated each other. It was the culmination of centuries of divergence rather than a single event.
The substantive issues. Papal authority — Rome claimed universal jurisdiction; the east held the Pope to be first in honour among five patriarchs but not a monarch over the church. The filioque — Rome inserted a clause into the creed stating that the Holy Spirit proceeds from the Father "and the Son", which the east regarded as an unauthorised alteration of a text agreed by an ecumenical council. And practical differences: leavened versus unleavened bread, clerical marriage, and language.
Underneath it was politics. Rome had allied with the Franks and crowned Charlemagne emperor in 800 (Chapter 7.4), which from Constantinople's point of view was the creation of a rival to the actual Roman emperor.
The split is not healed, and Orthodox and Catholic Christianity have been separate for a millennium.
The Fourth Crusade, 1204
The event that killed the empire, two and a half centuries before it formally ended.
A crusading army assembled at Venice, could not pay the Venetians for the ships it had ordered, and was diverted — first to attack a Christian city on the Adriatic to work off the debt, then to Constantinople to install a claimant to the Byzantine throne who promised payment. The claimant could not pay either.
So in April 1204 the crusaders stormed and sacked Constantinople. Three days of killing, rape and looting in the largest Christian city in the world, by an army that had taken the cross to fight in the Holy Land. Hagia Sophia was stripped; relics and treasures were carried off across Europe; the four bronze horses now associated with St Mark's in Venice were taken from the Hippodrome.
The empire was partitioned among the crusaders and Venice. Greek successor states survived, and Constantinople was recovered in 1261, and the empire never recovered its wealth, its territory or its fleet. From 1261 it was a small state living on diplomacy.
Pope John Paul II expressed regret for the sack in 2001, which gives some indication of how long the memory ran.
1453
Mehmed II besieged Constantinople in the spring of 1453 with an army of perhaps 80,000 against a defence of around 7,000.
The decisive factor was artillery. A Hungarian engineer named Orban offered his services to the emperor, who could not pay, and then to the Sultan, who could. He cast bombards firing stone balls of over 500 kilograms, and after seven weeks of bombardment the Theodosian Walls — which had stood for a thousand years against every previous technology — were breached.
Mehmed also had ships hauled overland on greased rollers into the Golden Horn, bypassing the chain.
The last emperor, Constantine XI, was killed in the final assault and his body was never identified. The city was sacked for three days by the terms of the period, and then Mehmed made it his capital.
Hagia Sophia became a mosque, then a museum in 1935 under the Turkish Republic, then a mosque again in 2020.
The consequences in Europe were substantial. Greek scholars fled west with manuscripts, feeding the Renaissance's recovery of Greek texts (Chapter 8.1). The eastern trade routes came under Ottoman control, which is one of the standard explanations for why Europeans started looking for a sea route to Asia (Chapter 8.4). And Russia claimed the inheritance — Moscow as the "third Rome", the Russian ruler taking the title Tsar, from Caesar, and the double-headed eagle.
What Byzantium actually contributed
Roman law, preserved and codified — the largest single item (Chapter 5.4).
Greek literature preserved. Nearly all surviving classical Greek texts come through Byzantine manuscript copies. Without the copyists of Constantinople there is no Plato, no Aristotle in Greek, no Homer, no Greek tragedy.
A shield. For eight centuries it absorbed Persian, Arab, Bulgar, Rus and Turkish pressure on Europe's southeastern approach.
Orthodox Christianity and the Slavic alphabet. Missionaries — Cyril and Methodius — devised a script for Slavic languages in the ninth century; Cyrillic is named for one of them. The conversion of the Rus, traditionally in 988, put Russia, Ukraine, Belarus, Serbia and Bulgaria into the Orthodox and Cyrillic sphere, and that division still runs through European politics.
Art and architecture. The dome on pendentives, the mosaic tradition, and the icon.
And a governing style. Complex bureaucracy, elaborate court ceremony designed to overawe visitors, and a diplomacy that preferred paying, dividing and marrying its enemies to fighting them — which is what "byzantine" was meant to mock and which is a reasonable strategy for a state with more money than manpower.
Where this shows up in your life
The alphabet used by around 250 million people.
The Orthodox churches, with roughly 220 million adherents.
Every legal system on the continental European model, which is most of the world outside the English-speaking countries.
And the correction this chapter argues for. The standard European story treats the millennium between Rome and the Renaissance as a gap. For most of that period the largest, richest, most literate Christian state in the world was operating continuously from Constantinople, and the largest, richest, most learned civilisation of all was operating from Baghdad and Cordoba (Chapter 7.2). The gap is in the telling, not in the history.
What the next page covers
Western Europe in the same centuries was genuinely poorer, less literate and less urbanised — and it was building institutions that would later matter enormously. Chapter 7.4 covers Europe after Rome — what feudalism actually was as an arrangement, why the Church became the only continent-wide institution, the agricultural changes that quietly tripled output, the rise of towns and the merchant class, and the invention of the university as a self-governing corporation, which is the institutional form Chapter 7.2 identified as the one that compounded.