The fans of chariot racing in 6th Century Constantinople were known to be pretty rowdy. The fans of the Blue and Green teams would often be in opposition, and would also get pretty political - think of them as a combo of a sports fan group, a street gang, and an actual political party. Being a fan of either color would often signify that you supported This or That claimant to the throne or come down on one side of a theological dispute. So it wasn't JUST sports.

There would be pretty frequent riots and clashes, though the biggest one occurred in 532. During this riot many thousands of people were killed and much of the city burned - it in some ways turned into a full on rebellion, thought it began at the chariot races.

The Blues and Greens united to storm the palace and put the Emperor's nephew, Hypatius, onto the throne. Eventually the Emperor sent some of his men bearing gold into the Hippodrome to speak to the leaders of the Blues. They gave the gold, of course, and also reminded them that the true Emperor was a Blue, and that the man they were to put on the throne, Hypatius, was a Green. After some deliberation the Blues made a decision and vacated the Hippodrome. After they left the Emperor's men stormed in and slaughtered thousands of Greens and put Hypatius to death.