Caligula is the nickname of the third Roman emperor, Gaius Julius Caesar Augustus Germanicus, who ruled from 37 CE until his death by assassination in 41. Though popular at the beginning of his reign, Caligula allegedly underwent a change in personality after a serious illness just a few months after gaining the throne, becoming a dangerous and possibly insane despot.
The emperor and the Senate were in the middle of a prolonged political dispute of unclear origin by the year 39, and he became extremely unpopular. Outlandish stories of his excesses, including incest, bestiality, and appointing his horse as Consul, abounded, and it is difficult to separate fact from fiction in early accounts of his reign.
Caligula was the great grandson of the first Roman emperor, Augustus. His father, Germanicus, was the commander of the Roman forces in Germania, modern-day Germany, and the army adopted the young Caligula as a mascot. His nickname means "little boots" and refers to the miniature army uniform that he was often dressed in. Though Germanicus was poised to succeed Tiberius as Emperor, he died in 19. Twelve years later, after spending his childhood in the care of various relatives, the 19 year-old Caligula went to live with his adopted grandfather Tiberius on the island of Capri.
Tiberius was fond of Caligula and appointed him to an honorary quaestorship in 33. When Tiberius died in 37, Caligula became the new emperor to the delight of the Roman people. He was nearly universally loved during the first few months of his reign, and when he fell ill in October, widespread mourning followed. The emperor recovered completely, although the illness may have led to later insanity. It is unclear when or how gradually the change in Caligula's ruling style occurred, but by the year 39, public opinion regarding the Emperor had reversed.
Caligula and the Senate became rivals. The emperor was criticized for his unsuccessful military campaigns in the north and for his attempt to tax such things as marriage. His attempts to present himself as a deity were also unpopular.
Augustus had instituted the Imperial Cult, in which the Roman emperor was deified, during his reign, but Tiberius did not promote it heavily. Under Caligula, the Imperial Cult was revived, but altered to make Caligula himself divine, whereas Augustus had denied such power, rather specifying that divine spirits surrounded him because he was the emperor. Caligula demanded personal worship and had the faces on statues of gods and goddesses throughout the empire replaced with his own likeness. This policy caused trouble particularly in the eastern fringes of the empire, as it conflicted with the monotheism of the Jews.
Cassius Chaerea, a centurion in the Praetorian Guard, led a group of guards in the emperor's assassination in 41. It was not the first attempt on Caligula's life. According to various Roman accounts, Chaerea's motives were either personal or political — perhaps a combination of both. Caligula allegedly humiliated Chaerea on a regular basis by calling him degrading names and making reference to an injury Chaerea had suffered to the groin. The assassins struck Caligula while he was giving a speech to a group of actors, and his wife and infant daughter were murdered as well.
Outrageous stories regarding Caligula's cruelty, depravity, and insanity made their way into the works of Roman historians such as Suetonius and have contributed to the popular view of the emperor ever since. In modern popular culture, his name is a byword for sadism and excess. While some of the stories regarding Caligula's insane behavior are nothing more than gossip, most historians agree that he was, at the best, inept as a ruler.