Caligula (12–41 CE) was the third Roman emperor, governing from 37 CE until his assassination in 41 CE. He belonged to the influential Julio-Claudian dynasty and assumed the throne following the demise of his great-uncle, Tiberius. According to ancient records, Caligula's reign commenced with widespread public approval. However, this goodwill dissipated within months as he began to rule through fear and brutality. His rule concluded when he was murdered by officers of his own personal guard, the Praetorian Guard.
Born Gaius Julius Caesar Germanicus in 12 CE, the future emperor was the son of the widely admired general Germanicus. His father was the nephew and adopted son of Emperor Tiberius, which positioned Gaius within the imperial succession. His mother, Agrippina the Elder, was the favored granddaughter of Augustus, Rome's first emperor. The family was immensely popular, and their children were cherished by the Roman public. As a young child, Gaius traveled with his father to military camps on the Rhine frontier. The soldiers were charmed by the toddler dressed in a miniature soldier's uniform and gave him the nickname "Caligula," meaning "little military boots."
Tragedy disrupted his childhood. Germanicus died suddenly in 19 CE while on a diplomatic mission in the eastern provinces. Poison was suspected, and Agrippina believed Emperor Tiberius was responsible. This accusation created a permanent rift between Agrippina and the emperor. In 29 CE, Tiberius ordered Agrippina exiled to a remote island, where she reportedly endured beatings and died from starvation in 33 CE.
This devil-may-care attitude helped keep him alive. So, too, did his friendship with the prefect of the Praetorian Guard, Naevius Sutorius Macro. Sensing that an early friendship with the young prince might pave his own way to power, Macro supported Caligula and went to great lengths to convince Tiberius that he was obedient and loyal. Eventually, the emperor lowered his guard enough to arrange a marriage between Caligula and Junia Claudilla, the daughter of the influential senator Marcus Junius Silanus. But still, Tiberius refused to trust Caligula completely and kept him on Capri for seven years. It was during this time, Suetonius claims, that Caligula first showed signs of the "cruelty and deviant appetites" for which he would become infamous:
Caligula's two older brothers were exiled and later declared enemies of the state, leading to their deaths. Soon after, Caligula himself was summoned to the island of Capri, where Tiberius lived in seclusion. It was evident that Caligula was not a guest but a political hostage. He understood that a single misstep could result in his execution. The historian Suetonius recorded that Caligula behaved as if the destruction of his family had "quite slipped his mind."
His cautious conduct, combined with his friendship with the powerful Praetorian Guard commander Macro, ensured his survival. Macro advocated for Caligula, persuading Tiberius of the young man's loyalty. Tiberius eventually arranged a marriage between Caligula and Junia Claudilla, the daughter of a prominent senator. Despite this, Tiberius detained Caligula on Capri for seven years. Suetonius claims it was during this prolonged captivity that Caligula first exhibited signs of the extreme cruelty that would define his later rule. He is said to have enjoyed observing torture, visited taverns in disguise at night, and engaged in numerous affairs.
Tiberius did not curb this behavior. He reportedly relished the idea that he was "rearing a viper" for the Roman people. While Tiberius initially favored his own grandson, Tiberius Gemellus, as his successor, he ultimately named both Caligula and Gemellus as joint heirs in his will in 35 CE, perhaps recognizing his own advanced age and Gemellus's youth.
Emperor Tiberius died on 16 March 37 CE. Some accounts state his death was natural, while others allege Caligula and Macro suffocated him. Regardless of the circumstances, Caligula was swiftly proclaimed emperor. With crucial support from Macro and his father-in-law, the Senate disregarded Tiberius's will, disinherited Gemellus, and granted Caligula sole authority. They conferred absolute power upon him, making him the first emperor to receive all imperial powers in a single act.
At twenty-five years old, Caligula's initial actions were promising. He provided Tiberius with a magnificent funeral, sponsored extravagant public games, and halted the politically charged treason trials that had characterized the previous reign. He released individuals imprisoned for political reasons, abolished certain unpopular taxes, and distributed a cash gift to every citizen of Rome. He also arranged for the remains of his mother and brother to be returned to Rome for a proper burial. For several months, his rule appeared to herald a new golden age.
In October of 37 CE, Caligula contracted a severe and mysterious illness that brought him to the brink of death for nearly a month. During this crisis, his close allies, Macro and Silanus, fearing for their futures, began making preparations for a successor. They turned their attention to the now-eligible Tiberius Gemellus. When Caligula made a miraculous recovery, he interpreted their actions as a profound betrayal.
His retaliation was immediate and ruthless. Gemellus was accused of treason and compelled to drink poison. Macro was appointed to a prestigious governorship, but upon arriving to depart for his new post, he was arrested and forced to commit suicide. Silanus, recognizing his inevitable fate, took his own life at home. The ease with which Caligula eliminated his most powerful supporters alarmed the Senate, but more disturbing behavior was yet to emerge.
Caligula's treatment of a high-ranking man like Atanius betrayed a contempt for the whole social order. He particularly resented the Roman elite, fearful that they were always plotting against him. In 38 CE, he reinstated the very treason trials that he had abolished the year before; the political prisoners he had freed were rearrested, as were dozens of others who showed some kind of offense. Suetonius writes that Caligula had several people of honorable rank disfigured with hot irons before condemning them to the mines, or to be torn apart by wild beasts, or to be sawn in half. When an equestrian who had been thrown to the beasts loudly protested his innocence, Caligula removed him from the arena, tore out his tongue, and threw him back in. Suetonius adds that when Caligula had someone executed, it was by often means of repeated and delicate cuts so that "a man would die knowing he was being put to the blade" (Suet., Gaius, 29).
Suetonius wrote that after his illness, Caligula was transformed from a princeps, or "first citizen," into a "monster." He discarded his earlier populist policies and embraced outright cruelty and paranoia. One illustrative incident involved a Roman knight named Atanius Secundus, who had vowed to fight as a gladiator if the emperor recovered. Caligula insisted he fulfill his promise, and the untrained man was swiftly killed in the arena.
Caligula's disdain extended to the entire Roman aristocracy. In 38 CE, he revived the treason trials. Suetonius documents that he ordered high-ranking individuals to be disfigured, sent to labor in mines, or executed by wild animals. He took pleasure in psychologically tormenting powerful figures. While dining with two consuls, he laughed and remarked that he could have their throats cut with a single nod. His most famous taunt was his threat to appoint his racehorse, Incitatus, as a consul, a direct mockery of the Senate's dignity. His most audacious act was to declare himself a living god and demand formal worship from his subjects.
Caligula maintained exceptionally close relationships with his three sisters: Agrippina the Younger, Julia Drusilla, and Julia Livilla. He honored them publicly, even featuring their portraits on coins. His devotion to Drusilla was particularly intense, and some later sources propagated rumors of an incestuous relationship, though these claims are considered unreliable. He married Drusilla to his friend Marcus Lepidus and designated Lepidus as his heir. When Drusilla died in 38 CE, Caligula was devastated. He declared her a goddess and ordered the construction of statues in her honor.
Caligula was married four times. His first wife, Claudilla, died. He quickly divorced his next two wives. His fourth and final marriage was to a woman named Caesonia. Ancient writers described her as unattractive, but she bore Caligula his only child, a daughter named Julia Drusilla after his beloved sister.
In 39 CE, Caligula traveled to Germany to command the Rhine legions, hoping to secure military glory matching that of his father. However, his campaign against Germanic tribes was a failure. He blamed others for the debacle, executing his general Gaetulicus and forcing his former heir, Lepidus, to kill himself. He also exiled his two surviving sisters and confiscated their property, leaving himself increasingly isolated and paranoid.
In 40 CE, he secured the annexation of Mauretania, one of Rome's most important client kingdoms in North Africa. Emboldened by this success, he began planning an invasion of Britannia and even raised two fresh legions for the occasion. But for one reason or another, the invasion never materialized. Though ancient sources blame Caligula's own cowardice, it is more likely that the soldiers mutinied – the infamous story of Caligula having his men collect seashells on the beaches of the Channel could have been some form of disciplinary exercise. Nevertheless, later that year, the emperor was determined to celebrate his power. He had a mighty pontoon bridge built from the resort of Baiae across the Gulf of Naples. Over the course of a splendid two-day celebration, Caligula rode across the bridge, wearing the supposed breastplate of Alexander the Great. This was probably a grandiose response to Thrasyllus's earlier prediction that Caligula was as likely to become emperor as he was to ride across the sea.
In 40 CE, he successfully orchestrated the annexation of Mauretania in North Africa. Emboldened by this, he planned an ambitious invasion of Britannia and raised new legions for the purpose. The invasion never materialized. Ancient historians claim his soldiers mutinied; one famous anecdote states he ordered them to collect seashells from the English Channel coast as a humiliating punishment. Later that same year, he constructed an enormous floating bridge across the Bay of Naples. He famously rode across it wearing the breastplate of Alexander the Great, an act possibly intended to mock a prophecy that he could only become emperor if he rode a horse across the sea.
Caligula's cruelty was not reserved for senators alone. He persistently ridiculed a Praetorian Guard officer named Cassius Chaerea for his high-pitched voice, derisively calling him "girl" and assigning him insulting daily passwords. On 24 January 41 CE, Chaerea's patience expired. As Caligula was passing through a secluded palace corridor, Chaerea and another tribune, Cornelius Sabinus, ambushed and stabbed him to death.
The conspirators then located Caligula's wife, Caesonia, and their infant daughter. Caesonia reportedly told them to "finish the last act of the drama." They killed her and then murdered the child by smashing her head against a wall. Although some senators hoped the assassination would restore the Roman Republic, the Praetorian Guard instead discovered Caligula's uncle, Claudius, hiding behind a palace curtain and proclaimed him the next emperor.
Murdered at just twenty-eight years of age, Caligula's name has become synonymous with madness and tyranny. While much of this notorious reputation is arguably deserved, it is crucial to acknowledge that our primary historical sources were senators who despised him and had motive to tarnish his legacy. The complete truth about Caligula may remain elusive, but his brief and violent reign endures as one of the darkest and most compelling chapters in the history of imperial Rome.
Only 28 when he was murdered, Caligula has gone down as one of history's mad rulers, his name synonymous with murderous excess and tyranny. While this reputation is certainly deserved to some extent, it is important to remember that most of those who wrote about him were from the senatorial class that he hated and had good reason to smear his name; in other words, it is best to take some facts about his cruelty with a grain of salt. Though we may never know the truth about who Caligula really was, his name and legacy loom large in the story of the Roman Empire.