The Roman Empire 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 West Asia ruled by emperors. From the accession of Caesar Augustus to the military anarchy of the third century, it was a principate with Italy as metropole of the provinces and its city of Rome as sole capital. Although fragmented briefly during the military crisis, the empire was forcibly reassembled, then ruled by multiple emperors who shared rule over the Western Roman Empire and over the Eastern Roman Empire. Rome remained the nominal capital of both parts until 476 AD, when it sent the imperial insignia to Constantinople following the capture of Ravenna by the barbarians of Odoacer and the subsequent deposition of Romulus Augustus. The fall of the Western Roman Empire to Germanic kings, along with the hellenization of the Eastern Roman Empire into the Byzantine Empire, conventionally marks the end of Ancient Rome and the beginning of the Middle Ages.