Byzantine is an art style associated with the Eastern Roman Empire from 330 to 1453. The city of Byzantium was a primary city for trade and culture, later to be named Constantinople by Emperor Constantine, and then Istanbul. Byzantine art is associated with the legalization of Christianity by Constantine and the church decor created to express Christian messages. The style shows Mary and Christ as more linear and flattened than the more naturalistic portrayals of earlier classical times. This selection of devotional icons replicate manuscript pages from the Old Testament and mosaics from the church walls.