The Eastern Roman Empire, like the Ancient Roman Empire, has well-developed associations, known as demes, which support the different factions (or teams) under which competitors in certain sporting events compete; this is particularly true of chariot racing.

There are four major factional teams of chariot racing, differentiated by the color of the uniform in which they compete; the colors are also worn by their supporters.

These are the Blues, the Reds, the Greens, and the Whites, although by the Eastern Roman era the only teams with any influence are the Blues and Greens.

Emperor Justinian I is a supporter of the Blues.

The team associations have become a focus for various social and political issues for which the Empire’s general population lacks other forms of outlet.

They combine aspects of street gangs and political parties, taking positions on current issues, notably theological problems (a cause of massive, often violent argument in the fifth and sixth centuries) or claimants to the throne.

They frequently try to affect the policy of the emperors by shouting political demands between the races.

The imperial forces and guards in the city cannot keep order without the cooperation of the circus factions, which are in turn backed by the aristocratic families of the city; this includes some families who believe they have a more legitimate claim to the throne than Justinian.

Some members of the Blues and Greens had been arrested in 531 for murder in connection with deaths that occurred during rioting after a recent chariot race.

Relatively limited riots are not unknown at chariot races, similar to the football hooliganism that occasionally erupts after an association football championship in modern times.

The murderers are to be hanged, and most of them are.

But on January 10, 532, two of them, a Blue and a Green, escape and take refuge in the sanctuary of a church surrounded by an angry mob.

Justinian is nervous: he is in the middle of negotiating with the Persians over peace in the east, there is enormous resentment over high taxes, and now he faces a potential crisis in his city.

He declares that a chariot race will be held on January 13 and commutes the sentences to imprisonment.

The Blues and Greens respond by demanding that the two men be pardoned entirely.