The Roman Emperor Who Reportedly Planned to Make His Favourite Racehorse a Consul of Rome Before His Praetorian Guard Stabbed Him in a Palace Corridor in 41 CE

Gaius Julius Caesar Augustus Germanicus — nicknamed Caligula (“little boot”) since childhood — became emperor on 16 March 37 CE at age 24. His early reign was popular; a severe illness in late 37 CE preceded a change in behaviour that contemporary and near-contemporary sources describe as paranoid, cruel, and erratic.

Suetonius’s Caligula (chapters 55-58, written around 121 CE) records that the emperor kept his favourite chariot-racing horse Incitatus in a marble stable with ivory manger, purple blankets, and a household of slave-grooms. The horse was reportedly invited to imperial dinner parties as a guest of honour. Suetonius adds that Caligula “is said to have planned to make him a consul” — consulatum quoque traditur destinasse.

The phrase traditur destinasse (“is said to have intended”) is hedged. Suetonius does not assert that Caligula actually nominated the horse, only that the plan was rumoured. The most plausible modern reading (Aloys Winterling, 2011) is that the horse-consul rumour was a political joke that Caligula himself had made — a deliberate threat to the senatorial class that he could appoint anyone, even a horse, to the consulship. The senate took the joke as an insult; the joke was reported as policy by hostile later historians.

The assassination

By January 41 CE Caligula had alienated the Praetorian Guard officer corps through a sustained pattern of personal insult to its senior officers. The Praetorian tribune Cassius Chaerea — whom Caligula had repeatedly mocked as effeminate — organised a conspiracy with several senators and Praetorian colleagues.

The killing took place on 24 January 41 CE in a covered corridor between the Palatine Palace and an adjacent theatre. Caligula was returning from the morning’s theatrical performances. Chaerea and his co-conspirators surrounded him. Chaerea struck the first blow with a sword to the neck. Approximately 30 stab wounds were inflicted in total. Caligula was 28.

His wife Caesonia and infant daughter Drusilla were murdered the same afternoon — the daughter’s head reportedly smashed against a wall — to extinguish the immediate dynastic line.

The Praetorian Guard then found Caligula’s uncle Claudius hiding behind a curtain in the imperial apartments and proclaimed him emperor. Claudius reigned for 13 years before being poisoned (probably) by his fourth wife Agrippina to clear the throne for her son Nero.

The fate of Incitatus is not recorded.