The Eastern Roman Empire was the eastern half of the Roman world after AD 395, ruled from Constantinople. It outlived the Western half by nearly a thousand years and is the state that historians later called the Byzantine Empire.
Key takeaways
- The Eastern Roman Empire was ruled from Constantinople, which Constantine I founded as a second capital in AD 330.
- It survived the fall of the West in AD 476 and lasted until the Ottomans took Constantinople in AD 1453.
- On our map the empire stands at 1.94 million km² in AD 476, grows to 2.91 million km² under Justinian in AD 565, and ends at 22,624 km² in AD 1453.
- Its people called themselves Romans. The name Byzantine was invented after the empire had fallen.
How the Eastern Roman Empire worked
The Eastern Roman Empire was the part of the Roman world that kept going after the Western half broke up. Its capital was Constantinople, which Constantine I made a second capital, a "New Rome", in 330 [3]. After the permanent split of 395 the East was ruled by its own emperor, and when the last Western emperor lost his throne in 476 it was the only Roman empire left. In 480, the Eastern emperor Zeno dissolved the Western court and ruled as sole emperor [2].
Its language slowly moved from Latin to Greek. By the time of Justinian I, who reigned from 527 to 565, Greek was replacing Latin even in law and government [1].
Justinian then tried to win back the lost West and reconquered parts of Italy and North Africa. The gains did not last. Over the following centuries the empire lost ground to Persians, Arabs and others, recovered under rulers such as Basil II, and shrank again. In 1204 the Fourth Crusade sacked Constantinople and split its lands between Greek and Latin successor states. The Greeks regained the city in 1261, but the empire was never more than a regional power again [1]. On 29 May 1453, Sultan Mehmed II captured Constantinople and the last emperor, Constantine XI, died in the fighting [1].
Throughout this time its people called themselves Romans. The word Byzantine came into use only after the empire had gone [1], and the Byzantine Empire map on this site follows the same state date by date.
An example from our data
Our map has five key dates that show the Eastern empire. At AD 476 the outline measures 1.94 million km² across 19 provinces (the year 476 page). Justinian's reconquests lift it to 2.91 million km² and 30 provinces by AD 565 (the year 565 page). Our data describes that date as: Justinian I dies after reconquering Italy, North Africa, coastal Dalmatia and south-east Spain.
The later outlines are drawn differently. At AD 1000 the area is 854,602 km², at AD 1180 it is 591,029 km², and at AD 1453 just 22,624 km². These later outlines are built from modern regions, because the old province system no longer applies, so treat them as broad estimates, and compare them with the earlier province-based dates only roughly. The last outline, on the year 1453 page, covers just 2 modern countries.
A province that sat firmly in the East is Aegyptus, with its capital at Alexandria. Our data lists it as part of the Eastern half. For the bigger story of how the two halves compare, read East and West on the homepage.
The thing people get wrong
People often say the Eastern empire "stopped being Roman" at some point and became something else, called Byzantine. It did not. Its citizens never used the word Byzantine for themselves. They called their state the Roman Empire and themselves Romans [1], and they kept Roman law and the title of emperor. The label Byzantine is a convenience that modern historians use for the later, mostly Greek-speaking and Christian phase, and some historians would rather not use it at all [1]. The empire changed greatly across a thousand years, but there was no day when the Romans of the East decided they were somebody else.
Eastern vs Western Roman Empire
| Eastern Roman Empire | Western Roman Empire | |
|---|---|---|
| Capital | Constantinople | Milan, then Ravenna |
| Main language | Greek | Latin |
| Ended | AD 1453 | AD 476 |
| Later name | Byzantine Empire | None, it broke into kingdoms |
Frequently asked questions
Is the Eastern Roman Empire the same as the Byzantine Empire?
Yes. They are two names for the same state. Eastern Roman Empire stresses that it was the Roman Empire continuing in the East, while Byzantine Empire is the later label that modern historians use for it after about the fifth or sixth century.
When did the Eastern Roman Empire end?
In AD 1453, when Ottoman forces under Sultan Mehmed II captured Constantinople.
How big was the Eastern Roman Empire?
It varied hugely. On our map it measures about 2.91 million km² at its Justinian peak in AD 565, and only 22,624 km² at the end.
Sources
- Byzantine Empire, Wikipedia.
- Western Roman Empire, Wikipedia.
- Roman Empire, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against Ancient World Mapping Center outlines and Pleiades).