Emperor Justinian held chariot races in Constantinople, similar to the chariot races held in Rome. But rioting occurred often at these races, followed by hangings of those responsible. On January 10, 532, two murderers condemned to death escaped and hid in the sanctuary of a church. An angry mob surrounded them. One murderer was from each side of the team races: one Blue and one Green supporter.
Justinian appeased the mob by declaring that a chariot race would be held on January 13 at the Hippodrome. But after this new race, the bloody Nika riots broke out between the Blue and Green supporters. Opponents of Justinian considered seizing on this opportunity to overthrow him. Justinian would have fled, but his wife Theodora persuaded him to stay in power.
Justinian then ordered his generals to suppress the riot, and they trapped 30,000 in the Hippodrome and slaughtered them.