What were religion and beliefs like in Byzantium?

The Byzantines were Orthodox Christians in terms of religion and belief.

The center of this church was the city of Constantinople (Byzantium). The Patriarch residing there was the greatest religious leader of the Byzantine Empire. In the early stages of the Empire, there was no division between the Eastern and Western Churches regarding Christian beliefs. But later, as a result of various sects, numerous religious debates, and political events, the Eastern and Western Churches completely separated from each other. Thus, two Christian denominations emerged. Western Christians were called “Catholic,” and Eastern Christians were called “Orthodox.”