How Long Did the Roman Empire Last? Ways to Count
How long did the Roman Empire last? Compare 503 calendar years to the West's fall with about 1,480 to Constantinople, and see the counting rule.
Last updated October 2026
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The Roman Empire lasted 503 named calendar years from 27 BCE to 476 CE. Count through the eastern capital's fall in 1453, and the span is about 1,480 years. Those known totals include both endpoint years. World History Encyclopedia: Roman Empire World History Encyclopedia: 1453: The Fall of Constantinople
The entries follow World History Encyclopedia: Roman Empire, World History Encyclopedia: 1453: The Fall of Constantinople.
The shorter answer counts the western office. The longer answer includes its eastern survival. The Eastern Roman Empire was the same Roman state's surviving eastern government, despite major changes in its borders and language. World History Encyclopedia: Byzantine Empire
TL;DR: Start with Augustus in 27 BCE. To 476 CE, 27 + 476 gives 503 calendar-year labels, or 502 elapsed years. To 1453, the same method gives about 1,480 labels, or 1,479 elapsed years. Starting with Rome's traditional founding in 753 BCE counts the city's whole history, including its Kingdom and Republic.
How long did the Roman Empire last? At a glance
The entries follow World History Encyclopedia, World History Encyclopedia: Ancient Rome, World History Encyclopedia.
The founding date is traditional, rather than a proven day on which a city appeared.
| What is counted | Dates | Duration and counting rule | Status |
|---|---|---|---|
| Roman Kingdom, traditional chronology | 753–509 BCE | 244 elapsed years between year labels | Disputed |
| Roman Republic, conventional chronology | 509–27 BCE | 482 elapsed years between year labels | Reviewed |
| Empire through the West's fall | 27 BCE–476 CE | 503 inclusive calendar-year labels; 502 elapsed | Reviewed |
| Empire through Constantinople's fall | 27 BCE–1453 CE | About 1,480 inclusive labels; 1,479 elapsed | Reviewed |
| Rome's whole political story from its traditional founding | 753 BCE–1453 CE | 2,206 inclusive labels; 2,205 elapsed | Disputed |
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Why most counts start with 27 BCE
Augustus's settlement with the Senate is the usual boundary between the Republic and Empire. Rome already ruled a large land before that settlement. What changed was the form of rule, with lasting power held by one man. Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE)
That is why the beginning of Roman expansion is not the beginning used in the common duration answer. The Republic fought wars, ruled provinces and demanded tribute long before Augustus. It had an empire in the land sense before it had emperors in the later sense. World History Encyclopedia: Roman Republic
Julius Caesar's dictatorship also preceded Augustus. His murder did not restore a stable Republic. More civil war followed. Choosing Augustus's settlement provides a clear, widely used marker for the system that emerged from those wars. World History Encyclopedia
For the alternatives, including Actium and Caesar's dictatorship, see when did the Roman Empire begin. A duration is useful only when its starting event is stated.
Why the western count ends in 476
Odoacer deposed Romulus Augustulus in 476. Another western emperor was not named to rule in Italy in his place. That is the conventional endpoint for the Western Roman Empire. World History Encyclopedia: Fall of the Western Roman Empire
It is an endpoint for an office and government, rather than for all Roman people or culture. Roman landowners, officials, churches and law continued in the kingdoms that followed. A ruler could use Roman habits without being a western Roman emperor.
There is also a surviving claimant to consider. Julius Nepos had lost Italy but remained the recognised western emperor until his death in 480. Choosing that date adds four years to either form of the western calculation. The event is discussed in World History Encyclopedia.
The last Roman emperor page explains why Nepos and Romulus both appear in answers. The western fall page follows the end in more detail.
Why the eastern count reaches 1453
The court in Constantinople survived the western deposition. Its emperors still called their state Roman. They received Roman law and claimed the power of earlier Roman rulers. The name Byzantine is a later historical label for that eastern survival. World History Encyclopedia
Over its long life, the state changed. Greek became its main language. Its borders narrowed, expanded and narrowed again.
Christian worship shaped public life. Those changes do not require us to treat each phase as a wholly new state.
The capture of Constantinople by the Ottomans ended the rule of its final emperor, Constantine XI, in 1453. Using this event gives the long duration answer. It includes the eastern empire's history as well as the earlier united empire. World History Encyclopedia
The imperial story also contains a break in control of the capital. Crusaders captured Constantinople in 1204. Roman successor states survived outside it, and an emperor recovered the city in 1261. A duration ending in 1453 includes that period of displacement.
For the final siege, see when did the Eastern Roman Empire fall. For the stages before it, see when did the Byzantine Empire fall.
The arithmetic: BCE, CE and no year zero
The calendar passes directly from 1 BCE to 1 CE. One year lies between the same point in those two years. Adding the numbers alone would give two. So a calculation of elapsed years across that boundary must subtract one.
For the western count, the calculation is 27 + 476 − 1 = 502. For the eastern count, it is 27 + 1453 − 1 = 1,479. These totals use year labels. They do not count from the exact day one ruler rose to the day another fell.
The totals 503 and 1,480 count every named year touched by the period. That includes both end years. Both forms are understandable if the method is clear. Neither should be presented as an exact duration down to the last day.
This matters most when comparing answers that appear only one year apart. A writer using inclusive counting may have the same events in mind as a writer using elapsed years. The difference can come from arithmetic, without any disagreement over Roman history.
Kingdom, Republic and Empire are different spans
Rome's traditional founding date belongs to its earliest story, not to Augustus's government. The story of Romulus and Remus mixes memory with legend. It should be marked as tradition rather than treated as a dated construction record. World History Encyclopedia
The Kingdom and Republic also belong in a broad timeline of Rome. The narrower question about the empire usually begins later. Starting with the founding and ending with Constantinople's fall creates a very long span. But it includes changes in the form of government.
The conventional Republican span is useful for explaining that difference. Rome moved from royal rule to offices such as consuls, then to rule by emperors. Some Republican bodies survived under emperors. So the boundary describes a change in the balance of power. World History Encyclopedia
For the events inside these periods, use the Roman Empire timeline. It places the traditional founding, the Republic, Augustus and the eastern empire in order.
Verdict: How long did the Roman Empire last
Count 503 named years from Augustus to the West's fall. Include the eastern empire, and the total is about 1,480. State which endpoint you mean. For elapsed-year arithmetic, subtract one across the BCE–CE boundary.
Counting from Rome's traditional founding answers a broader question about Roman history. Keep the Kingdom, Republic and Empire distinct. Each had its own form of rule.
Sources checked for this page
- Roman Empire - World History Encyclopedia
- 1453: The Fall of Constantinople - World History Encyclopedia
- Byzantine Empire - World History Encyclopedia
- Ancient Rome - World History Encyclopedia
- Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE)
- Roman Republic - World History Encyclopedia
- Fall of the Western Roman Empire - World History Encyclopedia
Questions people also ask
Did the Roman Empire last 500 years?
The western count is often rounded to about 500 years. Its usual dates are 27 BCE to 476 CE, which touch 503 named calendar years.
Did the Roman Empire last 1,500 years?
Including the eastern continuation gives about 1,480 named calendar years from 27 BCE to 1453, often rounded to roughly 1,500.
Why do some counts give 502 years?
There is no year zero. Elapsed-year arithmetic across BCE and CE subtracts one: 27 + 476 − 1 = 502.
Does 753 BCE mark the start of the Empire?
No. It is Rome's traditional founding date. It begins the broad story of the city, before the Republic and Augustus's Empire.
Did the Eastern Roman Empire continue after 476?
Yes. The government in Constantinople survived the western deposition and continued to understand itself as Roman.
Does the Holy Roman Empire add more years to the count?
No. The later Holy Roman Empire was a different political state. Its history should not be appended to the ancient empire's duration.