"Alongside supplies of bread, the state also guaranteed public entertainment, which took place in the Hippodrome of Constantinople, renovated by Constantine I. This racing arena was designed to seat the entire population of the city, senators and dignitaries on the marble seats nearest the track, with the rest seated on wooden benches above, and even women and children packed into the standing room at the top. The Byzantines were passionate enthusiasts for horse and chariot racing and very partisan in their support for teams identified by colour. The Reds, Whites, Greens and Blues, imported from Rome, were organized by professional corporations. By the sixth century, only the Greens and Blues were significant, but they had become large, powerful bodies with full responsibility not only for racing but also for displays of gymnastics, athletics, boxing, wild animals, pantomime, dancing and singing, which filled the entractes between the races."
--from "Byzantium: The Surprising Life of a Medieval Empire" by Judith Herrin (published in US and Canada in 2008)