Born Gaius Julius Caesar Germanicus; Caligula was the nephew and adopted son of Emperor Tiberius; making him part of the Julio-Claudian dynasty. He earned the nickname 'Caligula' (little solder's boot) while accompanying his father; Germanicus; during his campaigns in Germania.

His mother; Agrippina the Elder; became entangled in a deadly feud with Emperor Tiberius that resulted in the destruction of her family and leaving Caligula the sole male survivor. After Tiberius' death in 37 CE; Caligula succeeded his grand uncle as emperor. Surviving sources of his reign are few and far between; but he is often described as initially being a noble and moderate ruler before descending into tyranny; cruelty; sadism; extravagance and sexual perversity.

Caligula was eventually assassinated in 41 CE by a conspiracy of courtiers; senators and officers within his own Praetorian Guard; who murdered him and his family. Attempts by some of the conspirators to re-establish the Roman Republic were thwarted when the Praetorian Guard immediately decalared Caligula's uncle; Claudius; the new emperor.