Empress Theodora

The Byzantine Empire (or Byzantium) was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the "Roman Empire" (Greek: Βασιλεία Ῥωμαίων, Basileia Rhōmaiōn) 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 paganism 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, but an important point is Emperor Constantine I's transfer in 324 of the capital from Nicomedia (in Anatolia) to Byzantium on the Bosphorus, which became Constantinople, "City of Constantine" (alternatively "New Rome"). The Roman Empire was finally divided in 395 AD after the death of Emperor Theodosius I (r. 379–395), thus this date is also very important if the Byzantine Empire (or Eastern Roman Empire) is looked upon as completely separated from the West. The transition to Byzantine history proper finally begins during the reign of Emperor Heraclius (r. 610–641), since Heraclius effectively established a new state after reforming the army and administration by introducing themes and by replacing the official language of the Empire from Latin to Greek.

The Church of San Vitale — styled an "ecclesiastical basilica" in the Roman Catholic Church, though it is not of architectural basilica form — is a church in Ravenna, Italy, one of the most important examples of early Christian Byzantine Art and architecture in western Europe. The building is one of eight Ravenna structures inscribed on the UNESCO World Heritage List.

Byzantine art is the term commonly used to describe the artistic products of the Byzantine Empire from about the 5th century until the Fall of Constantinople in 1453.

The term can also be used for the art of Eastern Orthodox states which were contemporary with the Byzantine Empire and were culturally influenced by it, without actually being part of it (the "Byzantine commonwealth"), such as Bulgaria, Serbia, or Rus and also for the art of the Republic of Venice and Kingdom of Sicily, which had close ties to the Byzantine Empire despite being in other respects part of western European culture. Art produced by Eastern Orthodox Christians living in the Ottoman Empire is often called "post-Byzantine." Certain artistic traditions that originated in the Byzantine Empire, particularly in regard to icon painting and church architecture, are maintained in Greece, Serbia, Bulgaria, Russia and other Eastern Orthodox countries to the present day.