Caligula’s father was Germanicus, a well-loved and respected Roman general. His mother was Agrippina the Elder, a granddaughter of Augustus, the first emperor.

He was born Gaius Julius Caesar. As a kid, he spent much of his time with his father’s armies out in the provinces. The soldiers gave him the nickname “Caligula,” which means “little boot.”

After his father died, he lived first with his mother, then with his great-grandmother Livia, and later with his grandmother Antonia. His family suffered badly under Tiberius. His mother and two brothers were exiled or killed after being accused of plotting against the emperor.

Caligula was spared and sent to live with Tiberius on Capri. He spent several years by the emperor’s side, learning how Roman politics and government worked. Tiberius eventually named Caligula and his cousin Tiberius Gemellus as joint heirs. When Tiberius died in 37 AD, Caligula took the throne.

Caligula is remembered mainly for the excesses that came later, but his reign began with a short stretch of popular, moderate rule. He gave back many privileges to the people, freed innocent prisoners, and ended arbitrary treason prosecutions. He was also generous, handing out money to the public and putting on lavish games and shows.

Militarily, he acted fast in 39 AD to shut down a brewing revolt in Germany and executed the conspirators. Some historians even argue that he was a more capable military planner than his reputation suggests. His campaigns in Gaul helped keep Roman power secure in Europe and may have helped set the stage for the later invasion of Britain.

On the administrative side, he strengthened the emperor’s control over the army by moving the last legion under a senatorial governor in Africa to an imperial commander. He also started or planned big building projects, including a scheme to cut a canal through the Isthmus of Corinth. He briefly brought back a sense of order and hope after Tiberius’s gloomy reign.

After that good beginning, his rule took a sharp turn toward tyranny.

He burned through the huge treasury Tiberius had built up. To pay for his lavish spending, he turned to extortion, seizing the estates of wealthy citizens and placing heavy taxes on people.

About seven months into his reign, Caligula became seriously ill. After he recovered, his behavior reportedly changed dramatically. He brought back treason trials, executed many senators and knights, and humiliated the Senate by making its members run alongside his litter or fight for his entertainment.

His military campaigns also became a source of ridicule. His campaign in Gaul was essentially a looting expedition. His planned invasion of Britain ended in farce when he had his troops gather seashells on the beach and called them “spoils of the conquered ocean.”

Caligula also demanded to be treated like a god, which deeply offended many Romans. He planned to put a statue of himself in the Temple at Jerusalem, a move that could have set off a massive revolt. These actions contributed to several plots against him, and his own Praetorian Guard eventually assassinated him in 41 AD.

Caligula ruled for under four years, from March 37 AD until he was killed on January 24, 41 AD.

His death left a short, chaotic gap in power. The Senate saw a chance to bring back the Republic and started debating a return to the old system. That hope was quickly crushed by the Praetorian Guard, the emperor’s elite bodyguards.

While the senators argued, the Praetorians found Caligula’s uncle Claudius hiding in the palace and declared him emperor on the spot. They then forced the Senate to approve their choice, making it clear that the power to choose an emperor now belonged to the army, not the Senate.