Byzantine adj.

pertaining to Byzantium (q.v., original name of Constantinople, modern Istanbul), 1770, from Late Latin Byzantinus; originally used of the style of art and architecture developed there 4c.-5c. C.E.; later in reference to the complex, devious, and intriguing character of the royal court of Constantinople (1937). As a noun from 1770. Byzantian is from 1610s.