Ivory and Bone Casket with Warriors and Dancers Byzantine 1000-1100 CE probably Constantinople

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.

Ivory is a term for dentine, which constitutes the bulk of the teeth and tusks of animals, when used as a material for art or manufacturing. Ivory has been important since ancient times for making a range of items, from ivory carvings to false teeth, fans, dominoes, joint tubes^{[citation needed]}, piano keys and billiard balls. Elephant ivory has been the most important source, but ivory from many species including the hippopotamus, walrus, mammoth, sperm whale, and narwhal has been used. The word ultimately derives from the Ancient Egyptian âb, âbu "elephant", through the Latin ebor- or ebur.

The use and trade of elephant ivory has become controversial because it has contributed to seriously declining populations in many countries. In 1975 the Asian elephant was placed on Appendix One of the Convention on International Trade in Endangered Species (CITES) which prevents international trade between member countries. The African elephant was placed on Appendix One in January 1990. Since then some southern African countries have had their populations of elephants "downlisted" to Appendix Two allowing sale of some stockpiles.