The Byzantine Empire (or Byzantium) was the Eastern Roman Empire during Late Antiquity and the Middle Ages, centered on the capital of Constantinople. Known simply as the "Roman Empire" (Greek: Βασιλεία Ῥωμαίων, Basileia Rhōmaiōn; Látìnì: Imperium Romanum) or Romania (Ῥωμανία) to its inhabitants and neighbours, it was the direct continuation of the Ancient Roman State and maintained Roman state traditions. Byzantium is today distinguished from ancient Rome proper insofar as it was oriented towards Greek culture, characterised by Christianity rather than Roman polytheism, and was predominantly Greek-speaking rather than Latin-speaking. As the distinction between Roman Empire and Byzantine Empire is largely a modern convention, it is not possible to assign a date of separation; however, important points are the Roman Empire's administrative division into western and eastern halves in 285 by Emperor Diocletian (r. 284–305), and Emperor Constantine I's (r. 306–337) decision in 324 to transfer the capital from Nicomedia (in Asia Minor) to Byzantium on the Bosphorus, which became Constantinople, "City of Constantine" (alternatively "New Rome").