Anthony Kaldellis on the Roman Empire, Byzantium, and the Rise and Fall of Empires

Historian Anthony Kaldellis argues that the ‘Byzantine Empire’ never existed — the state that fell in 1453 was the same Roman Empire founded in 753 BC, unbroken in law, citizenship, and self-identity — and uses that 2,200-year span to explain why this particular state proved so durable: not through the virtue of individual emperors, but through taxation, law, and a monarchy that never quite escaped its republican origins.

Key ideas

1. Byzantium is Rome, not a successor state. ‘Byzantine Empire’ is a name invented by later historians, mostly to let Western Europe disown the Greek-speaking, Christian continuation of Rome. The polity’s own subjects called it Romania and called themselves Romans, without interruption, from the ancient republic to the fall of Constantinople.
2. The monarchic republic. No emperor held a hereditary right to rule. Legitimacy was earned continuously — through public acclamation at gatherings like the Hippodrome, functioning as something close to a perpetual referendum — and could be lost: 46% of Constantinopolitan emperors were deposed by violence, and roughly 120 civil wars occurred across the thousand years Kaldellis studies. Civil war, not any modern check, was the actual constraint on power.
3. Taxation is the empire’s skeleton. Kaldellis names taxation, not religion or military dictatorship, as the single institution that bound a vast and diverse population together for over a millennium. The Edict of Caracalla (212 AD), which extended Roman citizenship to nearly all free inhabitants of the empire, was enforced, not merely proclaimed — within a generation, provincials held the empire’s highest offices.
4. Crisis and recovery, not decline and fall. The empire’s history is a repeating pattern of brief, external shocks — the Arab conquests, a triple invasion by Seljuks, Pechenegs, and Normans in the eleventh century — followed by long stretches of endogenous consolidation and regrowth. Kaldellis argues historians should define the society by its recoveries, which came from within, not by its crises, which came from without.
5. Rome absorbed Christianity, not the reverse. Constantine’s conversion, probably sincere, brought a small (roughly 10%), politically marginal faith into the imperial system; full Christianisation took five more centuries. Because Christianity makes exclusive truth claims, it was simultaneously a more powerful unifying identity and a more polarising force than the religions it replaced.

Content

Byzantium is Rome — the long Roman Empire

Kaldellis opens by dismantling the label itself. ‘Byzantine Empire’ is a name applied centuries after the fact, largely by Western European historians who wanted the medieval Greek-speaking, Christian state in Constantinople to read as something other than Rome — a ‘Byzantine’ curiosity rather than the awkward, undeniable continuation of the empire that Western Europe had claimed as its own inheritance. The people who lived in that state called it Romania. They called themselves Romans, all the way through to 1453 and beyond. Kaldellis uses the Ship of Theseus as his working analogy: every component of Roman society changed across 2,200 years — language, religion, capital city — but the narrative thread, a continuously recognised political community, never broke. This differs from, say, Greek culture, which is not tied to any one state and can travel wherever people adopt it as their prestige tradition. Roman identity is specifically the history of a political community, the res publica of Roman citizens, and at no point in that community’s life did its members believe something dramatic had ruptured their membership in it.

That does not mean any two Romans, taken from different centuries, would recognise each other easily. A senator from Cicero’s Rome and a Greek-speaking, Orthodox Christian subject of eleventh-century Constantinople would look thoroughly foreign to one another — but so, Kaldellis points out, might a Roman senator and the enslaved son of a war captive living in the same city at the same time. Continuity is a property of the story a political community tells about itself, not of shared lived experience across its members.

The monarchic republic

Much of the conversation turns on a structural puzzle: the East Roman emperor held, in practice, enormous executive power, yet the polity never stopped calling itself a res publica — a commonwealth, a common concern, to be served rather than owned. Kaldellis calls the result a monarchic republic. No emperor possessed a hereditary right to the throne; each had to make and remake his legitimacy continuously. The mechanism was not periodic election but something closer to a perpetual referendum: at the Hippodrome, at military musterings, in churches, wherever large numbers of Romans gathered, the crowd’s acclamation or its silence and booing told an emperor, in real time, whether his rule still held. In 1195, Emperor Alexius III proposed a new tax to pay off a German extortion demand, announced it to a hostile Hippodrome crowd, and reversed the policy within the same speech.

The corollary is that civil war — 120 of them across the thousand years Kaldellis studies, with 46% of emperors deposed violently — functioned as the actual check on power, in place of the institutions a modern reader would look for. Kaldellis is direct that this was not sentimental: emperors who behaved well did so because misrule created genuine, structural risk of being overthrown, not because good governance was the polity’s natural default. He argues this rules out reading the East Roman state as a straightforward military dictatorship: unlike most authoritarian regimes across history, its emperors almost never turned the army against their own civilian population as an instrument of control, precisely because the army was recruited from, and lived among, that same population.

Taxation as the empire’s skeleton

Asked to name the one factor that explains how the empire actually worked, Kaldellis answers without hesitation: taxation. Every arable parcel of land was censused, in some periods for centuries running; taxes were collected roughly three times a year, in coin, in kind, and in services and military recruits. Kaldellis rejects, at length, the scholarly myth of the isolated peasant community unaware of or unaffected by the imperial state — even the most remote hermits are described in the sources by how far they managed to get from the tax census, which tells its own story about how total that reach was understood to be.

The Edict of Caracalla (212 AD, formally the Constitutio Antoniniana) is the pivotal moment in this argument. Before it, at most a third of the empire’s free population held Roman citizenship; the rest lived under local law. Caracalla’s edict extended citizenship to nearly all free inhabitants of the empire — and, unlike comparable gestures in most other empires, it was enforced. Within a generation, emperors and the most powerful officials in the empire came overwhelmingly from the provinces. Kaldellis contrasts this directly with the British Empire, which never extended equivalent metropolitan rights to its colonial subjects: ‘it’s almost impossible to imagine’ Britain making Indian subjects eligible for the throne. The edict, he argues, helped drain discontent from provincial populations during the Crisis of the Third Century that followed — a population with a genuine stake in the imperial system has less reason to rebel against it.

Crisis and recovery, not decline and fall

Kaldellis’s central historiographical argument is against reading Roman history as a slow, continuous decline. He identifies a small, discrete number of crises — the Crisis of the Third Century (235–284 AD, 26 emperors murdered in 50 years, hyperinflation, plague, temporary territorial fragmentation into breakaway ‘empires’); the near-simultaneous collapse under Persian and then Arab invasion in the seventh century, which cost the empire Egypt, Syria, and Palestine; and an eleventh-century triple invasion by Seljuk Turks, Pechenegs, and Normans that ended two centuries of Macedonian-dynasty expansion. Each was sudden, externally caused, and devastating. But each was also followed by a long stretch of consolidation and steady, endogenous regrowth — nobody arrived from outside to rebuild the Roman state; it rebuilt itself, every time but the last.

Kaldellis argues that historians of Byzantium have traditionally over-weighted the crises, in part because a ‘decline and fall’ framework primes the field to look for internal rot whenever the state hits trouble. His preferred emphasis runs the other way: define the society by what happens in the centuries-long valleys between crises, not by the crises themselves, because it is in those valleys — institutions, taxation, law, the daily mechanics of holding a huge population together — that the empire’s genuine distinctiveness lies. Even the eleventh-century collapse, he argues against the traditional ‘moral decay’ reading, is better explained by the near-simultaneous arrival of three structurally different enemies than by any internal weakness peculiar to the Macedonian-era state.

Constantine, Justinian, and the shift east

Constantine emerges from the conversation as Kaldellis’s single most consequential emperor — not the most admirable one; he had his own son Crispus and his wife executed without public explanation — but the one whose decisions, founding Constantinople in 330 AD and steering the empire toward Christianity, were irreversible and, on balance, beneficial at world-historical scale. Constantinople’s site, at the hinge between the Danube and Euphrates frontiers and between Europe and Asia, let emperors respond to threats from either direction and ended the empire’s earlier tendency to split at the Bosporus during civil wars (the fracture line later moved west, to the Adriatic). Its population grew from a small town of perhaps 20,000–25,000 to half a million within two centuries, driven almost entirely by forced immigration — some 2,500 senatorial households, each with large staffs, relocated by imperial order, and a grain dole (extended to as many as 200,000 residents) diverted directly from Rome’s own supply.

Justinian (527–565 AD), a peasant’s nephew who rose through the same channels of social mobility Kaldellis emphasises throughout, is presented as Kaldellis’s most genuinely double-edged figure — he could not decide whether to place him on his best- or worst-emperor lists, and put him on neither. Justinian’s committee, led by the jurist Tribonian, produced the Corpus Juris Civilis, the codification that is substantially the source of Roman law as studied today (Constantinople, not ancient Rome, is where the surviving text comes from). He also launched wars of reconquest in North Africa, Italy, and southern Spain that Kaldellis judges only partly successful: North Africa likely paid for itself, but Italy did not, and stripping the eastern frontier of troops to fund the western campaigns left Antioch exposed to Persian sack — ‘I don’t think you get a pass for conquering North Africa by surrendering Syria.’ The same reign includes the brutal suppression of the Nika riots (532 AD, over 30,000 dead) and the construction of Hagia Sophia, and Kaldellis argues for a moderate reading of the Plague of Justinian’s mortality against maximalist estimates of 50%, on the grounds that Justinian’s multi-front wars and tax collection show no narrative pause during the outbreak.

Near-death and recovery: Persia, the Arabs, and Greek fire

The seventh century brings the empire closest to actual extinction. A 602–628 AD war against Sasanian Persia — triggered by Heraclius’s own civil war against the usurper Phocas — left both empires exhausted just before a newly unified Arab army, having first united Arabia under Islam, struck both simultaneously from a direction neither had ever needed to defend. Kaldellis treats the resulting Arab conquests of Syria, Palestine, and Egypt (630s–640s) as close to overdetermined given the state both empires were left in. The loss of Egypt ended Constantinople’s grain supply and the city’s population fell for decades. Recovery took the rest of the century: a withdrawal to defend Asia Minor, the development of Greek fire — a closely guarded incendiary weapon deployed by ship-mounted siphon and, in a form Kaldellis notes as a genuine surprise to most listeners, hand-thrown grenades — and the successful defence of Constantinople against two Arab sieges. Kaldellis is also sceptical of how much weight the following iconoclasm controversy over religious images deserves: his own reading of the sources finds no evidence of popular engagement, only a few hundred emperors, bishops, and monks — a caution about mistaking the concerns of a literate elite, who wrote the surviving texts, for the concerns of the wider society.

Why it lasted, and why it finally didn’t

Asked directly why the state proved so resilient, Kaldellis gives a two-part answer: first, that the authorities made a sustained and largely sincere effort to persuade subjects they ruled on their behalf, and mostly did rule that way; second, that Roman and Orthodox Christian identity was tightly unified against neighbours who held neither. Structurally, he points to an absence: unlike almost every comparable pre-modern state, the Roman polity never saw a successful internal secession (with the single exception of Bulgaria, achieved only in 1185 after two centuries of intermittent rebellion), never lost the ability to tax its territory, and was never formally partitioned by its own elites. The final decline, in his dating, begins in the early fourteenth century: the loss of Asia Minor by around 1300 removed one of the empire’s two territorial ‘wings’, after which civil wars and Serbian territorial gains removed the last strategic slack. Constantinople’s fall in 1453 came over a century later than it might have, delayed in part by Timur’s unrelated defeat of the Ottoman Turks around 1400. Kaldellis is unequivocal that the cause throughout was external — ‘no wonder it didn’t survive’ a location at the crossing point of empire-building and new religions — not any internal source of decomposition.

Lessons for the present

Closing, Kaldellis draws two lessons for modern great powers, offered without endorsing any particular form of government: institutions that visibly work for the benefit of the ruled — and are credibly explained as such, not merely imposed — serve the ruling class’s own long-term interest, even where they cost it in the short term; and rhetoric that is not backed by matching action does not merely fail to persuade, it corrodes legitimacy over time, in contrast to what he sees as a wide and repeated gap between stated aims and actual conduct in modern American foreign policy. He identifies only three qualitatively distinct phases in human history so far — hunter-gatherer, agricultural, and the current industrial/technological phase — and closes on cautious optimism: by most measures, he argues, the scale of human misery has been falling, even as new categories of risk are being created alongside it.

See also

• Anthony Kaldellis — speaker
• Lex Fridman — host
• Long Roman Empire — the historiographical model this episode argues for
• Monarchic Republic — Kaldellis’s account of Roman/Byzantine political legitimacy
• Constantine the Great — founder of Constantinople
• Justinian I — codifier of Roman law and emperor of reconquest