Culture, style, and period of the Christian states of the eastern Mediterranean during the rule of the Byzantine Empire (330 - 1453 CE). Byzantine art and culture was carried throughout much of the Christian world, and lasted into the 16th century in eastern Europe. The style is characterized by imperial and religious subject matter, and a movement away from the original Greek naturalistic forms to favor ritualistic stylization, intended to suggest the spiritual. For the culture and style of the Italian and western Mediterranean Christian world roughly from the third to the mid-ninth century CE, use "Early Christian."

Source: Art & Architecture Thesaurus 

http://vocab.getty.edu/page/aat/300020669