The culture, styles, and period of the first centuries of Christianity, by some reckonings through the 9th century. In art, it generally refers to art of Italy and the western Mediterranean from the third to the mid-9th century CE. It is characterized by an adaptation of the artistic language and symbolism of classical antiquity, but generally sacrifices classical ideals of physical beauty and technical perfection to emphasize spirituality and the immaterial world. For the culture, style, and period of eastern Mediterranean Christian from the 4th to the mid-15th century CE, use "Byzantine."

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300020665