Byzantine art, however, cannot be defined adequately in political or geographical terms. It did not come suddenly into being, and for a long time it might as properly have been called Roman as Byzantine. Nor did it cease in 1453, for during the second half of the 15th cent. And Byzantine art passed far beyond the territorial limits of the empire, to penetrate, for instance, into the Slav countries.
Byzantine art is, above all, a religious art.
Not that it treated religious subjects only. There was a fine efflorescence of the 'minor arts' of metal-work, textiles, carved ivories, enamels, jewellery, etc. Secular paintings and mosaics also adorned the imperial palaces. It is also a theological art, in the sense that the Byzantine artist did not aspire to freedom of individual interpretation but was the voice of orthodox dogma and subject to the Church which established the dogma. His function was to translate into the language of art, for the instruction and edification of the faithful, the thought of the theologians and the decisions of Councils.