
The imperial seat moved from Rome to Byzantium and following the collapse of the West in AD 476, it became its sole capital as Constantinople. The Empire was later ruled by multiple emperors who shared control over the Western Roman Empire and the Eastern Roman Empire. From the accession of Caesar Augustus as the first Roman emperor to the military anarchy of the 3rd century, it was a Principate with Italia as the metropole of its provinces and the city of Rome as its sole capital. As a polity, it included large territorial holdings around the Mediterranean Sea in Europe, North Africa, and Western Asia, and was ruled by emperors. The Roman Empire was the post- Republican period of ancient Rome.
