The Roman Empire (Latin: Imperium Rōmānum) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterranean Sea in Europe, North Africa, and Western Asia, ruled by emperors with centralized authority in the namesake capital of Rome, now in modern Italy.
From the accession of Caesar Augustus as the first Roman emperor to the military anarchy of the 3rd century, it was a principate with Italy as the metropole of its provinces and the city of Rome as its sole capital.
Later, the Empire was ruled by multiple emperors who shared control over the Western Roman Empire and the Eastern Roman Empire.
Rome remained the nominal capital of both parts until AD 476 when the imperial insignia were sent to Constantinople following the capture of the Western capital of Ravenna by the Germanic barbarians under Odoacer and the subsequent deposition of Romulus Augustulus.
The adoption of Christianity as the state church of the Roman Empire in AD 380 and the fall of the Western Roman Empire to Germanic kings conventionally marks the end of classical antiquity and the beginning of the Middle Ages.
See also
Byzantine Empire - the eastern half of the Roman Empire which survived until 1453
