Nika riots

For about a week in January 532, rival fans of the chariot races in Constantinople joined forces against the emperor Justinian I, burned much of the city, including its great church of Hagia Sophia, and proclaimed a rival emperor. Justinian, reportedly stiffened by his wife Theodora, held on, and his troops ended the uprising with a massacre in the Hippodrome. The revolt takes its name from the rioters' rallying cry, Nika, meaning "Win!" or "Conquer!".

Chariot racing in the Roman world was organised around teams known by their colours. By the sixth century only two mattered, the Blues and the Greens. Their supporters' associations were part sports clubs, part street gangs and part political lobbies, and crowds used the races to chant demands at the emperor. Violence between the factions was common. Justinian, who came to the throne in 527, had once favoured the Blues but later tried to stand above both and curb their power, which alienated both sides.

Justinian's government was unpopular for other reasons too. His officials John the Cappadocian and the jurist Tribonian were blamed for heavy taxes and accused of corruption, and John's taxes fell hard on the wealthy senatorial class. The emperor's great reform of Roman law, which had begun quickly, had slowed. His war against the Sasanian Empire, after early victories at Dara and Satala in 530, had gone badly with defeat at Callinicum in 531, and peace talks were under way.

After a race riot in 531, the city prefect Eudaimon had several Blues and Greens condemned for murder. On 10 January 532, the scaffold broke during the hangings, and two survivors, one Blue and one Green, were taken to sanctuary in a church. Justinian commuted their sentences to imprisonment and announced races for 13 January, but the factions demanded full pardons.

On 13 January the crowd in the Hippodrome, next to the imperial palace, jeered the emperor throughout the races. By the last race the two factions were chanting "Nika" together, and they then attacked the palace. Fires spread through the city centre over the following days and destroyed Hagia Sophia. Justinian offered more races, then dismissed John and Tribonian as the crowd demanded, and finally appeared holding a Bible, apologised and promised an amnesty. Much of the crowd rejected him and acclaimed Hypatius, a nephew of the former emperor Anastasius I, as emperor. Whether Hypatius was a willing candidate is uncertain.

Justinian considered fleeing by sea. According to the historian Procopius, Theodora told the council that she would rather die an empress than live as a fugitive, saying that royal purple made a fine burial shroud. Modern historians treat the speech as a literary reconstruction of the debate rather than her exact words, and some argue that Justinian may in fact have briefly left the palace.

The emperor's men then acted. The eunuch Narses entered the Hippodrome with gold and reminded the Blue leaders of Justinian's past support, and the Blues broke away from the crowd. Troops under the generals Belisarius and Mundus then forced their way into the packed Hippodrome and cut down those inside without distinction. Procopius gives a figure of about 30,000 dead, many perhaps crushed in the panic. Hypatius and his brother Pompeius were executed, and senators who had supported them were exiled and lost their property.

Justinian rebuilt the city and Hagia Sophia, and presented his victory as the defeat of a usurpation. He later returned titles and land to the children of Hypatius and Pompeius and reinstated John the Cappadocian. The factions were not destroyed, and serious fighting broke out again in 565. Historians still debate the causes, from Justinian's inconsistent handling of the factions to the role of senators who exploited the unrest.

Our 500 map shows the Byzantine Empire shortly before Justinian's reign, with Constantinople, today's Istanbul in Turkey, as its capital; the 600 map shows it a generation after his death.