The Rise and Fall of the Roman Empire and the Byzantine Empire | Lex Fridman Podcast #498

Summary · 5 min read instead of 3 h 52 m

Kaldellis is a historian of the Roman Empire and author of The New Roman Empire, a comprehensive history of the Byzantine (Eastern Roman) Empire. He also wrote Streams of Gold, Rivers of Blood, on the period from 955 to the First Crusade. He is starting a book on why the Roman state lasted so long.

Kaldellis argues that the so-called Byzantine Empire was the Roman Empire, a continuous political community whose members always called themselves Romans. He says emperors had no right to the throne and faced frequent overthrow, so they had to win public consent through rhetoric and action. He gives taxation as the main force binding the society together. He sees the empire's crises as sudden outside shocks and its recoveries as the product of internal stability. In his view, foreign invasion, not internal rot, ended it in 1453.

Minute by minute

1. 1:44

   The Byzantine Empire was the Roman Empire. Kaldellis says the burden of proof lies on those who claim the Eastern Empire was something other than Rome. Its sources are clear that it called itself the Roman Empire and its subjects called themselves Romans to the end. He says Western Europeans had political reasons to label it the Empire of the Greeks and later Byzantine, and that this model is now collapsing.

2. 10:15

   Three swift crises, long slow growth. Kaldellis names three moments of fast territorial loss: the Arab conquests of the 630s, the Seljuk Turk conquest of Asia Minor in the 1070s, and the Fourth Crusade in 1204. He says the rest of the empire's history was mostly consolidation and slow, steady economic growth. He adds that dates like 395 and 476 label long processes, not single events.

3. 26:05

   Emperors projected a consistent public persona. Kaldellis says emperors presented themselves in laws, rhetoric and petition replies as responsive, accountable, proactive and tireless. Justinian was publicly known as the sleepless emperor. Citing Machiavelli's lesson to judge rulers by deeds, he says his research finds the authorities generally did what they said, though not perfectly.

4. 32:14

   No right to the throne kept emperors responsive. Kaldellis says the emperor emerged from the Republic and had no hereditary claim, so every emperor was vulnerable. He counts about 120 civil wars in the thousand years he studies and says roughly 46 percent of Constantinople's emperors were overthrown by violence. He describes the Hippodrome as a perpetual referendum, citing Alexius III dropping a German tax after an uproar.

5. 47:27

   Caracalla's edict made citizenship nearly universal. Kaldellis says Caracalla's edict of 212 extended Roman citizenship to nearly all free inhabitants, when perhaps a third at most held it. He says it was meant seriously: within a generation all emperors were provincials. That made it less of a leap to build a new center of Roman power at Constantinople a century later.

6. 57:12

   Diocletian turned the third-century crisis around. Kaldellis says the third-century breakaway empire in Gaul was a bid for the whole Roman throne, not separatism. Diocletian shared power among four emperors, a tetrarchy, and built a larger bureaucracy, army and universal tax census. He ended Italy's tax exemption. Kaldellis calls taxation the one factor at the heart of the society, and says tying farmers to land was a fiscal measure, not a caste system.

7. 1:14:48

   Constantinople sat at the empire's strategic hinge. Kaldellis says Constantine won the civil wars by 324 and founded Constantinople at Byzantium as a copy of Rome. The site lay between the Danube and Euphrates frontiers and joined Europe to Asia. A new senate of elites from the eastern Mediterranean tied them to it. He ranks Constantine first among emperors for the consequence of his decisions, not for his character.

8. 1:26:49

   Rome captured Christianity more than the reverse. Kaldellis leans toward the view that the imperial system co-opted Christianity. He says Christians may have been about 10 percent of the empire under Constantine, mostly urban and not elite. He finds no convincing political motive for the conversion and leans toward personal belief. He says the empire became majority Christian by roughly the fifth century, through funds for bishops and laws restricting traditional religion.

9. 1:52:18

   Barbarian armies and lost revenue broke the West. Kaldellis says Constantinople grew from perhaps 25,000 people to 500,000 in two centuries through migration. He explains the West's fall as a cycle: invading armies seized provinces, the state lost their taxes, and it could not fund armies against the next wave. The East survived partly through geography, since the Goths without a fleet could not cross into Asia Minor, and it later reconquered parts of the West.

10. 2:12:00

    Eunuchs balanced the established bureaucracy. Kaldellis says palace eunuchs handled the emperor's household and absorbed public resentment. Emperors used them as a parallel channel of power because they usually lacked family networks and depended entirely on the emperor. He cites the eunuch Narses, Justinian's general against the Goths in Italy. He also rejects the idea of isolated peasant communities outside the state.

11. 2:30:21

    Kaldellis sees Justinian's conquests as overreach. Kaldellis says Justinian codified Roman law through a committee under Trebonian, work that remains the main source for Roman law. His western conquests ravaged Italy and stripped the east of armies, letting the Persians destroy Antioch. He counts the Nika suppression, with more than 30,000 dead, against him. He argues the plague of 541 had a more moderate impact than the 50 percent some scholars claim.

12. 2:47:19

    Persian war and Arab conquests exhausted Rome. Kaldellis says Heraclius' rebellion diverted armies from the Persian front, then he defeated Persia with help from Turkish allies. The Arabs soon took Syria, Palestine and Egypt, cutting Constantinople's grain supply. The empire stabilized slowly behind a fortified Asia Minor and fleets armed with Greek fire. Leo III, with Bulgar allies, defeated the second Arab siege of Constantinople.

13. 3:10:41

    External shocks, internal recovery. Kaldellis attributes the eleventh-century crisis mainly to simultaneous attacks by Seljuk Turks, Pechenegs and Normans, though the end of the Macedonian dynasty also strained the budget. He says each crisis came from outside, while recovery came from within. He wants his field to explain the long periods of stabilization instead of centering the crises.

14. 3:21:31

    Foreign invasion ended a stable state. Kaldellis dates the point of no return to between 1300 and 1350, after the loss of Asia Minor, civil wars, Serbian expansion and the Black Death. He says there were no provincial separatist movements except Bulgaria, no warlord partitions, and no loss of the ability to tax. He credits stability to the authorities' effort to persuade subjects they ruled on their behalf and to a tightly unified Roman and Orthodox identity.

Published Jun 30, 2026.