The Nika riots were a major disturbance that occurred in Constantinople, driven by deep-seated frustration among the populace, particularly the chariot racing fans of the Blues and Greens factions. Unlike typical rivalries, this time both factions united against their common adversary—Emperor Justinian I. The riots erupted during a chariot race at the Hippodrome in January 532, where the crowd's grievances about increasing taxes and autocratic governance surged into open rebellion. Protesters called for the ousting of Justinian, chanting 'Nika,' which means 'victory' in Greek.

As violence escalated, the rioters took control of significant parts of the city, setting large sections ablaze, including the famous Hagia Sophia, which had been in the process of construction. In response, Justinian, who at first hesitated, sought counsel from his wife, Theodora, who famously encouraged him to remain and fight for his throne. Demonstrating both military and political savvy, Justinian summoned his most capable generals, Belisarius and Narses, to restore order. The imperial forces launched a brutal counter-assault against the rioters, resulting in thousands of deaths and the violent suppression of the rebellion.

The aftermath of the Nika riots had profound implications for Justinian's reign. The emperor not only retained his authority but also took the opportunity to reconstruct Constantinople, leading to the enhancement of the city's infrastructure and the completion of the Hagia Sophia. This pivotal moment reinforced the power of the Byzantine Empire and Justinian's ambitious plans for legal and territorial expansion, known as the Justinian Code. The bloodshed and destruction transformed the political landscape, making clear the consequences of defying imperial authority.