Caligula: a biography

Full name: Gaius Caesar Augustus Germanicus

Born: August AD 12

Died: 24 January AD 41

Known for: Though he ruled Rome as Emperor for only four years, Caligula has been immortalised as one of history’s most cruel and erratic leaders. Earning the nickname Caligula – 'Little Boots' – in childhood, he would be immortalised as one of Rome's cruellest and most erratic leaders, even though he was only emperor for four years. Among the most famous incidents of his reign, he allegedly tried to make his horse a consul and was said to have declared war on the god of the sea, Neptune.

Reigned: March AD 37 until his death in January AD 41

Cause of death: He was assassinated by members of the Praetorian Guard, possibly in collusion with the Senate.

Succeeded by: His uncle, Claudius

The Roman Empire produced some spectacularly bad emperors over the centuries. There was the brutally egotistical Commodus, who moonlighted as a gladiator in the Colosseum, and the bizarre Elagabulus, who dressed in women’s clothing and got about the Palatine in chariots pulled by slave girls. Then there was Nero, whose orgies and tyrannical excesses were notorious.


No list of the worst Roman emperors would be complete without Caligula. Everybody 'knows', after all, of how he threw obscene orgies, had sex with his sisters and was an ingenious and sadistic torturer. And, of course, he was stark, raving mad. Yet most of what we think we know about Caligula comes from accounts (both ancient and modern) based on the authors’ highly active imaginations, rather than historical record.

It is true that few lives have come close to the absolute heights and profound depths Caligula experienced in just 25 years. He was the youngest son of Germanicus, the rising star of the imperial dynasty, and part of a revered family, which combined celebrity glamour with monarchy and a cult of personality.

Caligula's early life

As the youngest in this Roman pantheon, he was the ‘chick’, the darling, the mascot. The name Caligula, or ‘Little Boots’, came from adoring soldiers to whom Germanicus liked to display his son dressed as a miniature Roman legionary. Uncomfortable with the moniker, Caligula later insisted on the given name he shared with a famous ancestor – Gaius Julius Caesar. (Many historians today use Gaius rather than the sensational alter ego of Caligula.)

Caligula’s childhood idyll ended when his father apparently contracted a lethal dose of malaria in Egypt and died in the province of Syria, certain to the last that he had been poisoned. Almost the entire population of Rome turned out to receive his ashes, but significantly the emperor Tiberius was not present.

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Germanicus’s sons were potential successors to the emperor, making the family a threat to Tiberius’s second-in-command, the sinister Sejanus, who had ambitions of his own. By now, Tiberius was elderly and had withdrawn to his villa in Capri, leaving much of the governance of Rome to Sejanus.

Yet Sejanus could do nothing against his rivals while their protector Livia, the mother of Tiberius, was still alive. It was only after her death in AD 29 that Caligula’s mother and his two older brothers were arrested. The mother was flogged so badly that she lost an eye, and died soon afterwards (or was killed) in exile. Caligula’s brother Drusus was deliberately starved in his imprisonment until, in his hunger, he tried to eat the stuffing from his mattress. The other brother avoided a similar fate by committing suicide.

Before Sejanus could move against Caligula, however, he himself was executed when Tiberius awoke to the treachery of his scheming subordinate. Caligula, the last surviving son of Germanicus, was appointed the imperial heir and ordered to live with Tiberius in Capri.

The next six years were stressful beyond belief for Caligula. The biographer Suetonius tells us that he was scrutinised day and night for any signs of disaffection or hints of disloyalty, deliberate or unintentional. Let’s not forget that this was an era when a senator could be put to death for going to the toilet while wearing a ring with the emperor’s portrait.

Caligula's illness

Caligula went to bed every night wondering if he would be woken in the small hours and taken to the cells for summary execution. Even as Tiberius lay dying, the capricious emperor could have abruptly appointed a different successor, which would have meant certain death for Caligula as no other emperor could tolerate his claim to the empire.

Once Tiberius died, Caligula went literally overnight from a near-hostage to the acknowledged master of Rome. His return to the city was welcomed with wild enthusiasm. Soon afterwards, he had a nervous breakdown. In an age familiar with post-traumatic stress we should perhaps expect this. As veteran soldiers will testify, the true psychological impact is felt only upon returning to normalcy and safety, then experiencing utter alienation from others who have not shared the same experience. Caligula’s collapse left him bedridden in delirium while an anxious Rome prayed for his recovery. Ancient biographers report that he arose from his sickbed as a madman.

Marble statue of Tiberius. (Photo By DEA / G. DAGLI ORTI/De Agostini via Getty Images)
Marble statue of Tiberius. (Photo By DEA / G. DAGLI ORTI/De Agostini via Getty Images)

The truth proved to be worse though. Caligula, ruler of Rome, had been out of action for weeks – and nothing had happened. The provinces had been governed as usual, the senate met and passed decrees and the praetorian prefects administered justice. The empire had gone peacefully about its business. The way that the imperial system functioned meant that Rome did not actually need a hands-on ruler.

Caligula’s mental collapse left him bedridden in delirium while Rome prayed for his recovery

Caligula was not really necessary and, to someone with his upbringing, ‘unnecessary’ meant ‘disposable’. As a headstrong young man with a survival instinct ingrained across every fibre of his being, Caligula set about rectifying what he saw as an unacceptable situation. He would make himself necessary, and make the senate and the people of Rome dependant on his rule. It ended up being a flawed and fatal strategy, but it followed logically from Caligula’s life experience to date.

Caligula's feud with the Senate

He immediately jettisoned the example of his immediate predecessors, who had carefully pretended to work through the senate, even while slaughtering individual senators. By explicitly taking direct control of the empire, Caligula was not only ahead of his time, he was declaring war on the senate. Therefore, Caligula’s reign is not about the antics of a young madman, but the story of a political struggle for supremacy – a story told by the victors, for whom libel laws were non-existent and the truth optional.

The last ruler of Rome to openly place himself above the senate was Caligula’s namesake, Gaius Julius Caesar, and the Ides of March shows what they thought of that. Nevertheless, Caligula elevated himself above the senate by declaring himself a God. Later, that was less unusual – the emperor Domitian entitled himself Master and God – but at the time this seemed blasphemous and bizarre.

The senate twisted Caligula's every action. Mud was hurled with gleeful disregard for the truth

Even in Caligula’s time, it was not unprecedented. In the Greek east, rulers were almost routinely deified, and the divine status of the Egyptian pharaohs had been adopted by their Macedonian successors. Caligula awarding himself the same status in Rome was only insane in the sense that it was a political gambit certain to fail.

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Caligula the God had the support of the people and the army, but was a political neophyte with a personality totally unsuited to fighting a senate of ruthless fixers hardened by savage, often fatal, political battles. Senators had connections, clients and a hidden grip on the levers of power. Both sides in this struggle used any and all means at their disposal, but it was Caligula who was outmatched.

One of the weapons of the senate was propaganda. Here, a comment by the great orator Cicero is revealing: “I call this man a gladiator, not as the usual rhetorical insult, but because he really was one.” In other verbal attacks, Cicero labelled opponents as arsonists, patricides (even those with living fathers), pathics, coprophiliacs and murderers, and even claimed – with no proof whatsoever – that one man killed children to use their organs in necromantic rites. In Roman political invective, mud was hurled with gleeful disregard for the truth, just to see what would stick.

As for Caligula, the senate seized upon his claim of divinity and interpreted it as madness. They twisted every action of an emperor who was in any case young, headstrong and thoughtless, and simply invented other cases. Even the fact that his wife loved him was seen as evidence of his madness (he allegedly threatened to torture her to discover why). Caligula was also a loving father, but apparently only because his child shared his sadistic inclinations, which excused Caligula’s eventual murderers bashing the toddler’s brains out against a wall.

Painting of Agrippina
Agrippina Landing at Brundisium With the Ashes of Germanicus. (Photo by Francis G. Mayer/Corbis/VCG via Getty Images)

Was Caligula a bad emperor?

Staying with family relations, the biographer Suetonius reports that Caligula enjoyed sex with his sisters during banquets while appalled guests looked on. Yet Suetonius wrote a century later, when the legend of Caligula as a lunatic had been well established. By then, some believed he had become a sex-crazed madman because his wife had overdosed him with a love potion. Since much of the detail of Caligula’s mental state comes from Suetonius, the claim of incest merits further examination.

The historian Tacitus was born 15 years after Caligula died. Unlike Suetonius, he scrupulously reports allegations as just that – allegations rather than fact – and he does not mention any such dinner party entertainment. Nor does the philosopher – and senator – Seneca, who actually knew Caligula. Both writers do not shy away from the topic, but mention Caligula’s sister Agrippina in connection with incest only with her uncle and son, not her brother.

As to Caligula’s murderous side, there is a definite shortage of victims. While Suetonius is fond of saying the emperor had people slaughtered by the dozen, he is curiously reticent about naming them. Other writers, such as Appian and Plutarch, meticulously document the senators killed in the much bloodier purges of Sulla and the Triumvirs.

Caligula did order the execution of Tiberius’s son and his Praetorian prefect Macro (who appeared set on emulating Sejanus in ambition), as well as his cousin, the king of Mauritania. But most of his other victims are dubious, like the gladiator who died of an infected wound after Caligula had visited him. So in all there are less than a dozen names. Compare this to hundreds killed by Augustus, dozens by Tiberius, and many more by Nero and Claudius, with most of their high-ranking victims carefully named.

Relief depicting the procession that accompanied Augustus
Relief of the procession that accompanied Augustus. (Photo By DEA / A. DE GREGORIO/De Agostini via Getty Images)

As there is insufficient space to refute every allegation of Caligula’s madness, two examples must suffice. The first is Philo’s account of a meeting with Caligula. He and a group of ambassadors had travelled from Egypt to complain about the provincial governor, but Caligula was inspecting some mansions he had ordered so the unfortunate ambassadors had to run after him from room to room. Finally, Caligula ordered the breathless delegation to present their case.

Philo reckons he was dealing with a lunatic, yet this deranged conduct led to a rehearsed hours-long speech being compressed into a five-minute synopsis, after which Caligula decided in the delegation’s favour. He also inspected his buildings while he was at it.

Secondly, we are told that early in his reign Caligula had a sudden impulse to visit the army in Germany and dashed to the frontier with none of the usual preparations. Once there, he decided to kill the army commander and various soldiers. In truth, that commander was a general of suspect loyalty whom Tiberius had earlier ordered to Rome. The general knew he faced execution on arrival there, so replied that if he came he would bring his army; he then remained in Germany. Caligula’s sudden arrival caught him flat-footed and he was executed before rallying allies, whom Caligula subsequently purged. The move was bold, ruthless and decisive, but not necessarily insane.

After Caligula’s assassination four years after he took power, it became even more urgent to stress that he had been mad – he was still popular with the people and army despite his war with the senate. The new emperor Claudius was insecure in his position and the senate eager to justify Caligula’s killing – so, without Caligula present to retaliate, the damning of his name proceeded without restraint.

Dr Philip Matyszak is a historian and author of many books on ancient history

How did Caligula die?

The reviled emperor’s guards finally turned on him, writes historian Dominic Sandbrook

Cassius Chaerea was not a happy man at the turn of the year 41. An experienced officer in the Praetorian Guard, he had served on the Rhine and prided himself on his sense of honour. But like many other veteran figures in Rome’s political classes, Chaerea was increasingly disturbed by the tone of life under the nihilistic young Caligula.

To add insult to injury, the emperor treated Chaerea as a comic punch line. Caligula, wrote the historian Suetonius, “used to taunt him,
a man already well on in years, with voluptuousness and effeminacy by every form of insult”. When Chaerea asked for the watchword, Caligula would suggest “Venus” and “would hold out his hand to kiss, forming and moving it in an obscene fashion”. For Chaerea this was all too much. And when he heard of a plot against the insufferable emperor, he decided to play his part.

On 24 January, Caligula rose late and decided to go and see a troupe of young actors, who were rehearsing just below the palace. There are various accounts of what followed, but one common version is that, as he was returning through an underground corridor, one of Chaerea’s officers, Sabinus, asked the emperor for the day’s watchword.

“Jupiter,” Caligula said. “So be it!” Sabinus cried, and then, drawing his sword, slashed through the emperor’s jawbone. Caligula fell instantly. “As he lay upon the ground and with writhing limbs called out that he still lived,” wrote Suetonius, “the others dispatched him with 30 wounds; for the general signal was ‘Strike again.’” Tellingly, some “even thrust their swords through his private parts”.

The slaughter did not end there. A centurion was sent to kill Caligula’s wife, Caesonia, while his infant daughter, Julia Drusilla, was murdered by having her “brains knocked out against a wall”. But Cassius Chaerea did not live to enjoy his revenge. When Caligula’s uncle Claudius took over as emperor, one of his first acts was to order the execution of the assassins.

Caligula: four big questions about his life and reign answered


Did Caligula make his horse a consul?

Caligula had a favourite racehorse named Incitatus (The Swift). He gave the animal regular treats and a stable made from marble. Soldiers were ordered to hush the neighbourhood when the horse was sleeping. “It is even said he planned to make the horse a consul.” All the above comes from Suetonius. When even he repeats something as hearsay, it is time to be very wary.

Instead, the consul story has become part of the Caligula myth. In Robert Graves’s novel I, Claudius, Caligula makes the horse a senator, with the intention of making it a consul later, while in Lloyd C Douglas’s book The Robe he actually does the deed.

In reality, he did not. Perhaps he publicly quipped that even his horse would make a better consul than the present incumbents, and the senate propaganda machine took it from there. It is also possible that Caligula did seriously contemplate making his horse a consul, but as a way of demeaning the senate. Nero later tried to demean senators by making them fight as gladiators and by prostituting their wives.


Why was Caligula called Little Boots?

Technically, we are asking why is Caligula called Caligula? Caligula was a childhood nickname that stuck – much to his chagrin. The young Gaius Julius Caesar would be brought along with his father, Germanicus, on his military campaigns, decked out in a miniature soldier’s uniform made especially for him.

Troops, seeing him in toddler-sized armour and boots, started calling him ‘Caligula’, meaning ‘Little Boots’. Despite his dislike for the moniker when he grew up, he was forevermore known by it.


Did Caligula declare war on the sea?

Whether this actually happened is debatable. As the story goes, Caligula led an ill-conceived campaign to Britain, which made it to the furthest shores of Gaul before being aborted.

As returning to Rome without a victory was unthinkable, Caligula declared war on Neptune, god of the sea, and had the waves whipped. His soldiers were ordered to collect seashells as prizes of war.


Was Caligula a bad emperor?

Sometimes we only hear what we want to hear. When people start with an idea they want to be true, they may downplay or reinterpret anything that disagrees with it and enthusiastically accept anything that helps confirm it. (Anyone who has been wildly in love and later disillusioned will know this phenomenon.)

Until the concept was given its more scientific-sounding name – confirmation bias – this tendency would be described by the cynical saying, "Give a dog a good name and bless it, give a dog a bad name and hang it".

Thanks to Suetonius, confirmation bias has shaped our view of Caligula. Why did he commit his atrocities? Because he was mad.

How do we know he was mad? Because he committed atrocities.

Once we break confirmation bias, other motives become apparent. But then we have a mundane political power struggle, when we secretly prefer the delicious horror of an empire (safely distant from us) ruled by a sex-crazed, murderous tyrant.


This content first appeared in the January 2018 issue of BBC History Revealed and updated with content from the January 2020 issue of BBC History Magazine