The following outline is provided as an overview of and topical guide to the Byzantine Empire: Byzantine Empire (or Byzantium) – the Constantinople-centred Roman Empire of the Middle Ages. It is also referred to as the Eastern Roman Empire, primarily in the context of Late Antiquity, while the Roman Empire was still administered with separate eastern and western political centres. In its own time, there was no such thing as "the Byzantine Empire," there was just the ongoing Roman Empire; "Byzantine Empire" is a scholarly term of convenience to differentiate the empire from its earlier existence during classical antiquity before the western half collapsed (see decline of the Roman Empire). Its citizens continued to refer to their empire as the Roman Empire (Greek: Βασιλεία Ῥωμαίων, Basileia