Constantine the Great, the first Christian Roman Emperor, refounded the city of Byzantium and named it after himself, as Constantinople, in 330 AD. This area became known as the Byzantine Empire. Constantine established precedents for harmony of church and state that endured as long as the empire. The empire slowly formed a union of late Roman customs, Orthodox Christianity, and Greek language and culture.
Byzantine crosses have numerous versions. Some are plain and some have decorative etchings. Many, however, have two versions of Jesus Christ upon them, one side with arms outstretched straight from sides depicting crucifixion, and the other side with arms bent at the elbow, palms up, signifying the ascension.