https://www.smithsonianmag.com/history/blue-versus-green-rocking-the-byzantine-empire-113325928/
In the days of the Roman republic, the races featured four color-themed teams, the Reds, the Whites, the Greens and the Blues, each of which attracted fanatical support. By the sixth century A.D., after the western half of the empire fell, only two of these survived—the Greens had incorporated the Reds, and the Whites had been absorbed into the Blues. But the two remaining teams were wildly popular in the Eastern, or Byzantine, Empire, which had its capital at Constantinople, and their supporters were as passionate as ever—so much so that they were frequently responsible for bloody riots.
The Byzantine Empire at its height under the Emperor Justinian in c. 560. Map: Wikicommons.
Exactly what the Blues and the Greens stood for remains a matter of dispute among historians. For a long time it was thought that the two groups gradually evolved into what were essentially early political parties, the Blues representing the ruling classes and standing for religious orthodoxy, and the Greens being the party of the people. The Greens were also depicted as proponents of the highly divisive theology of Monophysitism, an influential heresy which held that Christ was not simultaneously divine and human but had only a single nature. (In the fifth and sixth centuries A.D., it threatened to tear the Byzantine Empire apart.) These views were vigorously challenged in the 1970s by Alan Cameron, not least on the grounds that the games were more important than politics in this period, and perfectly capable of arousing violent passions on their own. In 501, for example, the Greens ambushed the Blues in Constantinople’s amphitheater and massacred 3,000 of them. Four years later, in Antioch, there was a riot caused by the triumph of Porphyrius, a Green charioteer who had defected from the Blues.
Even Cameron concedes that this suggests that after about 500 the rivalry between the Greens and the Blues escalated and spread well outside Constantinople’s chariot racing track, the Hippodrome–a slightly smaller version of the Circus Maximus whose central importance to the capital is illustrated by its position directly adjacent to the main imperial palace. (Byzantine emperors had their own entrance to the arena, a passageway that led directly from the palace to their private box.) This friction came to a head during the reign of Justinian (c. 482-565), one of Byzantium’s greatest but most controversial emperors.
