Was Caligula Really Insane?

The Roman emperor Caligula, who ruled from 16 March 37 AD until his assassination on 24 January 41 AD, is undoubtedly one of the most notorious Roman emperors. Unfortunately, over the centuries, a tremendous mythology has grown up around him and many of the things that are popularly believed about him are simply not true.

Caligula is best known to the general public as an insane, sexually depraved emperor who thought he was a living god, murdered a little boy for coughing too much, had sex with all three of his sisters, murdered his sister who was pregnant with his child and ate the fetus, turned his palace into a brothel, drank expensive pearls dissolved in vinegar, made his horse a senator, and waged war against Neptune to collect seashells as “loot.”

These are all stories that have accumulated over the years. Most of them are definitely or probably false; others are based on historical facts but have been greatly misrepresented. Caligula was many things—including a jerk, a narcissist, a sadist, and a tyrant—but he probably wasn’t really insane.

Some sources of popular misconceptions about Caligula

Doing historiography is especially difficult when it comes to Caligula, since he began to be mythologized while he was alive and this mythologization has only proliferated over the course of the past two thousand years since his death. Exaggerated and colorful stories have piled on top of exaggerated and colorful stories and, as a result, Caligula seems to have grown even more insane with each passing generation.

There probably is at least some truth to Caligula’s sordid reputation. The surviving contemporary accounts of his reign unanimously portray him as a cruel tyrant. The Jewish Middle Platonist philosopher Philon of Alexandria (lived c. 20 BC – c. 50 AD) gives a first-hand account of his experience with Caligula in his Embassy to Gaius. The account is far from flattering. Philon came to the emperor as a member of a group of Jewish ambassadors; he claims that the emperor persistently belittled and insulted them and refused to listen to their concerns.

It is probably true that Caligula was something of a sadist. The Roman Stoic philosopher Seneca the Younger (lived c. 4 BC – 65 AD) describes Caligula’s sadism in his treatise On Anger, which he probably wrote in around 45 AD, only a few years after the end of Caligula’s reign. He writes in On Anger 3.18, as translated by Aubrey Stewart:

“Why do I pry into ancient history? quite lately Gaius Caesar flogged and tortured Sextus Papinius, whose father was a consular, Betilienas Bassus, his own quaestor, and several others, both senators and knights, on the same day, not to carry out any judicial inquiry, but merely to amuse himself.”

“Indeed, so impatient was he of any delay in receiving the pleasure which his monstrous cruelty never delayed in asking, that when walking with some ladies and senators in his mother’s gardens, along the walk between the colonnade and the river, he struck off some of their heads by lamplight.”

Seneca is probably exaggerating a bit here, but he’s probably not lying through his teeth; Caligula probably was a very brutal ruler.

Unfortunately, virtually all our surviving ancient sources about Caligula were written by elite Roman men, who despised him and saw him as the prototype of a “bad emperor.” We don’t know very much about what the common people thought of him.

ABOVE: Photograph from Wikimedia Commons of a Roman marble portrait bust of the Stoic philosopher Seneca the Younger, who portrays Caligula in his writings as a sadistic tyrant

One the most influential ancient sources about Caligula is a biography of him written by the Roman author Gaius Suetonius Tranquillus (lived c. 69 – after c. 122 AD), who worked as a secretary to the emperors Trajan and Hadrian. Suetonius was writing in around the year 121 AD, around eighty years after Caligula’s death, and he is a notoriously unreliable source—partly because he has a penchant for telling all kinds of crazy stories about the alleged sexual debaucheries of all the emperors he doesn’t like, including Caligula. His biographies read like modern gossip tabloids.

Caligula appears as a character in the bestselling novel I, Claudius by Robert Graves, which was published in 1934. Graves revels retelling in the same sorts of bizarre and horrifying stories told by Suetonius, often exaggerating these stories to make Caligula seem even more insane.

In 1976, Graves’s novel was adapted into an award-winning BBC drama, also titled I, Claudius, which is generally regarded as one of the best television shows ever made and is considered the direct precursor to modern shows like Rome and Game of Thrones. This drama, however, exaggerates the extent of Caligula’s alleged insanity even further than Graves’s original novel.

ABOVE: Title screen from the 1976 BBC drama series I, Claudius

In 1979, the notorious pornographic film Caligula, starring Malcolm McDowell as the titular character, was released. In sharp contrast to I, Claudius, this film quickly won a reputation as one of the worst films ever made. Its notoriety, however, only contributed to Caligula’s reputation for depravity and insanity.

More recently, the Netflix series Roman Empire has become another major source of misconceptions about Caligula. The series is neither a drama nor a documentary, but rather a bizarre hybrid of the two in which events are portrayed by actors in costumes, but there are experts (and some non-experts) talking the whole time, adding commentary.

The third season of the show, which became available for streaming on 5 April 2019, is subtitled Caligula: The Mad Emperor and is nominally about the reign of Caligula. As we shall soon see, many of the events portrayed in the series are completely made up. Unfortunately, because the series is presented as a docudrama rather than a straight drama, many viewers have been misled to believe that everything depicted in it is historically true.

ABOVE: Promotional image for Netflix’s 2019 docudrama series Roman Empire: Caligula: The Mad Emperor

His name

Now that we know where some of the misconceptions about Caligula come from, let’s talk about what those misconceptions are. We’ll start out with the fact that his real name was not Caligula, nor was he generally known by the name Caligula while he was emperor.

Caligula’s full name before he became emperor was Gaius Julius Caesar (which is, incidentally, the exact same full name as the more famous Gaius Julius Caesar who conquered Gaul and was assassinated on 15 March 44 BC). As a child, Gaius was brought up among the soldiers and he wore a smaller version of the outfits they wore. Soldiers in those days wore a kind of leather boot known as a caliga.

Since Gaius wore little versions of these boots, the soldiers nicknamed him Caligula, which is a diminutive form of the word caliga. In other words, his nickname literally means “Little Boots.”

ABOVE: Photograph of an actual ancient Roman caliga dated to the first century BC or first century AD that was discovered at the site of Qasr Ibrim in Egypt

ABOVE: Photograph from Wikimedia Commons of a man wearing a modern reproduction of an ancient Roman caliga

Upon ascending to the throne, Caligula took the official name Gaius Caesar Augustus Germanicus. He took the name Germanicus from his father, a popular general who had won many great victories in Germania and posthumously been awarded the title Germanicus.

Ancient authors record that, after he became emperor, Gaius absolutely detested it whenever anyone called him by the nickname Caligula or by his personal name Gaius. Seneca writes in his treatise De Constantia Sapientis, which he wrote in around 55 AD, not long after Caligula’s death, as translated by Aubrey Stewart:

“The same Gaius construed everything as an insult (since those who are most eager to offer affronts are least able to endure them). He was angry with Herennius Macer for having greeted him as Gaius—nor did the chief centurion of triarii get off scot-free for having saluted him as Caligula; having been born in the camp and brought up as the child of the legions, he had been wont to be called by this name, nor was there any by which he was better known to the troops, but by this time he held ‘Caligula’ to be a reproach and a dishonour.”

As Peter Gainsford argues in this blog post titled “What did Caligula think of his nickname?” the name that Caligula most likely preferred to be called by was actually Germanicus. This is the name that is most prominent on Caligula’s coins and the name that Caligula gave to the month of September when he renamed it after himself.

Nonetheless, all the ancient sources written within three centuries after Caligula’s death unanimously refer to him as “Gaius.” This is the name that Philon uses, the name that Seneca uses, the name that the Roman encyclopedist Pliny the Elder (lived c. 23 – 79 AD) uses, the name that Suetonius uses, and so on.

It is only in around the late fourth century AD that the sources start referring to Caligula by the name Caligula. Ancient authors most likely started doing this to belittle him by calling him a childish nickname that they knew he hated. (Incidentally, the notorious later emperor Elagabalus, whom I wrote about in this article from November 2019, wasn’t generally known by the name Elagabalus during his lifetime either; instead, he was known as Avitus or Marcus Antoninus.)

Even though it wasn’t his actual name, I do think the name Caligula is useful for historical purposes because it is unique and can only refer to one specific individual. Gaius, by sharp contrast, was an extremely common praenomen and the name Germanicus is far more closely associated with Caligula’s father than with the man himself. This is why, for the rest of this article, I will be calling the emperor in question “Caligula,” even though he was certainly not known by this name while he was emperor.

ABOVE: Photograph from Wikimedia Commons of an ancient Roman marble portrait head of the emperor Elagabalus, who was not generally known as Elagabalus during his reign

Caligula’s illness

In the 1976 BBC television series I, Claudius, episode nine (“Zeus, by Jove!”), Caligula is portrayed as suffering from frequent headaches and hearing a strange galloping in his ears. Then he falls into a coma, which lasts for an unspecified amount of time. When he finally awakens from the coma, he is portrayed completely delusional, believing that he is the god Zeus and that his sister Drusilla is the goddess Hera.

In the Netflix series Roman Empire: Caligula: The Mad Emperor, episode two (“A New Hope”), Caligula is portrayed as initially a good emperor. Then, only a few months into his reign, he suddenly and inexplicably falls into a three-month-long coma. The doctor who is caring for him tells Macro, the prefect of the Praetorian Guard, that he is probably going to die. Against all odds, Caligula finally wakes up, but, as a result of his illness, he swiftly transforms into a depraved psychopath.

The ancient sources do record that Caligula did fall seriously ill early in his reign and that there were fears that he might die, but none of them say anything at all about him falling into a coma (let alone one lasting for three months), nor do any of them say anything about the illness causing him to go insane. Caligula’s contemporary, the Jewish writer Philon of Alexandria, writes in his Embassy to Gaius 14, as translated by F. H. Colson for the Loeb Classical Library:

“But in the eighth month Gaius was struck down by severe sickness. He had exchanged the recent more homely and, therefore, healthier way of life which he had followed while Tiberius was alive, for one of extravagance. Hard drinking, luxurious feeding and appetites still unsatisfied when the cavities were stuffed full, hot baths, ill-timed, and acting as emetics, followed at once by renewed toping and gormandizing in its train, lasciviousness venting itself on boys and women, and everything else that can destroy soul and body and the bonds in both which keep them together, joined in the assault. Self-restraint is rewarded by strength and health, incontinence by infirmity and sickness bordering on death.”

This is the most detailed description of Caligula’s illness we have. Notice that Philon says nothing about any kind of headaches, nothing about the duration of the illness, nothing about any kind of coma, and nothing about the illness making him go insane. All he says is that Caligula was very sick, that the sickness was brought on by an unhealthy hedonistic lifestyle, and that there were fears that Caligula might die. That’s it.

Furthermore, not only is the whole thing about the three-month-long coma not in the ancient sources, but I genuinely don’t think it would be possible for a person in the ancient world to survive in a complete coma for three months. Coma patients generally lack a swallow reflex, meaning they cannot swallow food or drink.

The only way modern coma patients are able to survive for months or even years is because modern hospitals use feeding tubes. They didn’t have those in the ancient world, which means, if Caligula really had fallen into a complete coma, he would have most likely died of dehydration or starvation after about a week or two at most. In order for him to survive longer than that, he would have to either wake up every week or so before falling back into the coma or somehow still be able to swallow food and water while in the coma.

ABOVE: Screenshot of Caligula waking up from his implausible three-month-long coma in the Netflix series Roman Empire: Caligula: The Mad Emperor

Caligula the God

One aspect of Caligula that modern portrayals have especially focused on as a sign of his alleged insanity is his claim that he was a living god. In the 1976 television series I, Claudius, episode nine (“Zeus, by Jove!”), when Caligula awakens from his coma, he immediately demands to see his uncle Claudius, threatening to kill him if he doesn’t come.

When Claudius comes in, Caligula tells him that he has undergone a “metamorphosis” and that he has miraculously transformed into a living god. He also declares that his sister Drusilla has become a goddess. Claudius humors him, paying obeisance to him and telling him that he can see his divine radiance. Later, though, when Caligula is no longer present, Claudius is shown laughing with his friends, declaring that Caligula is insane and that, soon, his reign will be over and the Romans will restore the republic.

Throughout the rest of the episode, Caligula is portrayed as calling himself “Zeus” and Drusilla “Hera.” He starts dressing up as Zeus and he renovates the palace to make it look more like Mount Olympos. Things get even nuttier in episode ten (“Hail Who?”), in which Caligula actually performs a whole dance routine dressed as Eos, the Greek goddess of the dawn, wearing tons of makeup, a wig, and a gold bikini.

ABOVE: Screenshot from the I, Claudius episode “Hail Who?” of Caligula (played by John Hurt) performing his dance dressed Eos, the goddess of the dawn

An equally bizarre take on Caligula’s divinity appears in the 1979 film Caligula, which contains a scene in which Caligula appears before the Senate to make the following declaration:

“I have existed from the morning of the world and I shall exist until the last star falls from the night sky! Although I have taken the form of Caius Caligula, I am all men as I am no man and, therefore, I am… a god.”

Immediately after this declaration, some senators can be heard muttering that Caligula is crazy, but he declares that he awaits “the unanimous decision of the Senate.” At first, no one says anything, but Caligula starts shouting “Aye!” so the senators start shouting “Aye!” as well. Then Caligula starts baaing like a sheep, leading all the senators to start baaing like sheep as well. In the midst of all the baaing, Caligula leaps into the air and shouts that the period of mourning is now over.

At this point, Longinus, Caligula’s advisor, suddenly exclaims “He’s mad!”—as though this is something he has just realized. Then soldiers come out and start whipping all the senators, just as the black curtains of mourning come falling down from the ceiling on everybody’s heads.

ABOVE: Screenshot of Caligula (played by Malcolm McDowell) shouting “Aye!” to his proposition of his own divinity from the 1979 film Caligula

So, how much truth is there behind these portrayals? There is definitely some. Philon of Alexandria records in his Embassy to Gaius that Caligula overtly tried to portray himself to the public as a god and that he even ordered for a colossal statue of himself to be erected in the Holy of Holies in the Temple of YHWH in Jerusalem.

Philon describes at length how Caligula made public appearances dressed as demigods, including Herakles, the Dioskouroi, and Dionysos and how he eventually began dressing himself as full deities such as Hermes, Apollon, and Ares. He describes how this was seen as shocking and sacrilegious.

Despite all this, most of what we see in I, Claudius and Caligula is made up. Philon does not record Caligula as having regularly called himself “Zeus” and his sister Drusilla “Juno,” nor does he record him as having dressed up as Zeus, nor does he record him as having renovated the imperial palace to make it look more like Mount Olympos. (As we shall see in a moment, Caligula did deify Drusilla, but only after her death.) Perhaps most disappointingly, the bikini-clad dance routine from I, Claudius is pure fantasy.

Moreover, Caligula’s efforts to portray himself as a deity do not seem to have been the result of delusion, but rather part of a carefully-thought-out political strategy. This strategy ultimately didn’t pan out the way Caligula probably wanted it to, but it was well conceived nonetheless.

For centuries before Caligula, Hellenistic Greek rulers in the eastern Mediterranean had claimed that they were divine. Their alleged divinity was part of what gave them legitimacy. Meanwhile, the Romans themselves had a longstanding tradition of posthumously deifying great leaders. Julius Caesar had been declared a god shortly after his death, leading his grandnephew and heir Augustus to claim the title of divi filius, meaning “son of a god.” After his death, Augustus was likewise declared a god.

In claiming to be a living god, Caligula was really just trying to apply the Hellenistic model of divine kingship to the Roman Empire. The problem is that the Romans weren’t ready for that yet, so it backfired on him politically. This merely proves that Caligula was not very attuned to the political climate in which he lived—not that he was insane.

ABOVE: Photograph from Wikimedia Commons of a bronze Hellenistic Greek statue of a nude king or general, bearing a scepter. Divine kings were normal throughout the Hellenistic world.

Murder of Tiberius Gemellus

Caligula’s adopted son and presumed heir for the first part of his reign was Tiberius Gemellus. In I, Claudius, episode nine (“Zeus, by Jove!”), Gemellus is portrayed as a young child with a cough and Caligula is portrayed as having him murdered because he can’t get the sound of him coughing out of his head. When a soldier presents the emperor with Gemellus’s severed head, he declares, “I’ve cured his cough.”

In historical reality, Gemellus was not a small child, but rather a young man who was around nineteen years old at the time of his death. The reason why Caligula had him killed was not because he couldn’t get the sound of him coughing out of his head, but rather because he suspected that he had been plotting to usurp his power. The Roman historian Kassios Dion (lived c. 155 – c. 235 AD) records in his Roman History 59.8, as translated by Earnest Cary for the Loeb Classical Library:

“After this he [i.e. Caligula] fell sick, but instead of dying himself he caused the death of Tiberius [i.e. Gemellus], who had assumed the toga virilis, had been given the title of Princeps Iuventutis, and finally had been adopted into his family. The complaint made against the lad was that he had prayed and expected that Gaius would die; and he destroyed many others, too, on this same charge.”

Finally, the real Gemellus wasn’t beheaded, but rather forced to commit suicide.

The main reason why Gemellus is portrayed as younger in the series than he was in real life and the reason for his execution is portrayed as more arbitrary is to drive home the message that the fictionalized version of Caligula in the series is dangerous and insane.

ABOVE: Screenshot from the I, Claudius episode “Zeus, by Jove!” of Claudius and Caligula being presented with the severed head of Gemellus

Caligula’s incest

Caligula is famously alleged to have had sex with all three of his own sisters and to have treated his sister Drusilla as his wife. This is a story that is actually found in some ancient sources. The earliest surviving source that specifically claims these things is Suetonius’s Life of Caligula. Suetonius writes in chapter 24, as translated by R. C. Rolfe:

“He lived in habitual incest with all his sisters, and at a large banquet he placed each of them in turn below him, while his wife reclined above. Of these he is believed to have violated Drusilla when he was still a minor, and even to have been caught lying with her by his grandmother Antonia, at whose house they were brought up in company. Afterwards, when she was the wife of Lucius Cassius Longinus, an ex-consul, he took her from him and openly treated her as his lawful wife; and when ill, he made her heir to his property and the throne.”

“When she died, he appointed a season of public mourning, during which it was a capital offence to laugh, bathe, or dine in company with one’s parents, wife, or children. He was so beside himself with grief that suddenly fleeing the city by night and traversing Campania, he went to Syracuse and hurriedly returned from there without cutting his hair or shaving his beard. And he never afterwards took oath about matters of the highest moment, even before the assembly of the people or in the presence of the soldiers, except by the godhead of Drusilla.”

The problem here is that Suetonius is a relatively late, generally unreliable source. There are no earlier sources that explicitly claim Caligula had sex with his sisters, but there is some earlier evidence that scholars have interpreted as possibly supporting Suetonius’s account of Caligula’s incest.

Notably, there is concrete archaeological evidence that Caligula did exalt his sisters to an unusual extent. Surviving coins minted during Caligula’s reign depict his face on the obverse and his three sisters on the reverse, clearly labeled with their own names. The fact that his sisters appear on his coins is highly unusual and seems to confirm what Suetonius says about him giving them unusually prominent positions ahead of his own wife.

Of course, the fact that Caligula honored his sisters on coins doesn’t prove he was having sex with them. It is entirely possible that the real reason why Caligula honored his sisters so highly is simply because he wanted to emphasize the importance of the Augustan bloodline. All three of Caligula’s sisters were direct descendants of the emperor Augustus; none of his official wives shared this quality. By emphasizing the importance of the Augustan bloodline, Caligula may have been trying to reinforce his own legitimacy as emperor.

ABOVE: Photograph from Wikimedia Commons of a Roman sesterius minted c. 38 AD depicting Caligula’s head on the obverse and his three sisters—Agrippina, Drusilla, and Julia Livilla on the reverse

Further evidence of the high esteem with which Caligula’s sisters were held during his reign comes from the fact that there are a large number of surviving portrait heads representing them. Portrait types have been identified for all three of Caligula’s sisters, including Drusilla (who died early in his reign) and Julia Livilla (who was murdered shortly after his reign ended).

Once again, though, the fact that Caligula commissioned sculptures of his sisters doesn’t prove that he was having sex with them. After all, there are plenty of surviving sculptures of other imperial women, such as Livia (the wife of the emperor Augustus and mother of the emperor Tiberius) and Julia the Elder (Augustus’s daughter and Caligula’s maternal grandmother). Statues of imperial women simply aren’t very unusual.

ABOVE: Photograph from Wikimedia Commons of a marble portrait head believed to represent Caligula’s sister Drusilla

ABOVE: Photograph from Wikimedia Commons of a portrait bust of Caligula’s sister Julia Livilla on display in the Altes Museum in Berlin

Suetonius’s claim that Caligula had Drusilla deified after her death is confirmed by multiple independent contemporary sources. For instance, a dedication from the site of Caere dated to Caligula’s reign that is now on display in the Vatican Museums bears a Latin inscription that would have originally read “DIVAE DRVSILLAE SORORI CAII CAESARIS AVGVSTI GERMANICI,” which means “To the Divine Drusilla, sister of Gaius Caesar Augustus Germanicus.”

ABOVE: Photograph from Wikimedia Commons of an inscription from the site of Caere on display in the Vatican Museums bearing the dedication, “To the Divine Drusilla, sister of Gaius Caesar Augustus Germanicus”

Drusilla’s posthumous deification is also referenced by Seneca in his Apocolocyntosis Claudii or The Gourdification of Claudius, a satirical work making fun of the emperor Claudius and the Roman tradition of posthumously deifying emperors. In the very first section of the work, Seneca sarcastically remarks that the events he is about to describe may sound incredible, but you have to believe him because he heard it all from the same man who testified to the Senate that he had seen Drusilla ascending into heaven as a goddess. He writes, as translated by Allan Perley Ball:

“Who ever demanded affidavits from an historian? Still, if I must produce my authority, apply to the man who saw Drusilla going heavenward; he will say he saw Claudius limping along in the same direction. Willy-nilly, he has to see everything that happens in heaven; for he is the superintendent of the Appian road, by which you know both the divine Augustus and Tiberius Caesar went to join the gods.”

“If you ask this man he will tell you privately; in presence of more than one he’ll never speak a word. For since the day when he took oath in the Senate that he had seen Drusilla going up to heaven and in return for such good news nobody believed him, he has declared in so many words that he’ll not testify about anything, not even if he should see a man murdered in the middle of the Forum. What I have heard from him, then, I state positively and plainly, so help him!”

Deifying female members of the imperial family was extremely unusual in Caligula’s time. Even Livia was not deified until the reign of Caligula’s successor Claudius. The fact that Caligula had Drusilla deified does not prove that he had sex with her, but it does demonstrate the extent of his attachment to her.

ABOVE: Page from a ninth-century AD Latin manuscript of Seneca’s Apocolocyntosis Claudii

Thus, it seems that everything Suetonius says about Caligula’s relationship with his sisters is confirmed by earlier sources—except for his claim that Caligula was having sex with them. This leaves the question of Caligula’s alleged incest open for debate. It’s possible he may have really done it, but it’s also possible that it is simply a rumor invented by some senator who was annoyed that Caligula was showering extraordinary honors on his sisters while holding the Senate in the uttermost contempt.

If Caligula did indeed have sexual relations with his sisters, this still would not prove that he was insane because there are perfectly rational reasons why he might have done this. I’ve already mentioned that Caligula and his three sisters were all direct descendants of Augustus. If one of Caligula’s sisters bore him a son, that son would be the child of not one but two descendants of Augustus, which would make the child’s bloodline very secure indeed.

The kings of the Greek Ptolemaic Dynasty, which ruled Egypt from 305 BC until 30 BC, had been known for marrying their own sisters to keep their bloodlines pure. (As I discuss in this article from January 2020, Cleopatra VII Philopator, the last ruler of this dynasty, was the product of literally centuries of incest.) It is possible that Caligula may have simply been trying to do the same thing that the Ptolemies had done before him.

As we have already seen, the contemporary ancient sources are unambiguous about the fact that Caligula sought to portray himself as a deity. It so happens that the Olympian deities in Greek and Roman mythology were known for their many incestuous affairs. Zeus himself famous had sex with his sister Demeter and married his sister Hera. If Caligula really did have incestuous relations with his sisters, he may have done so in conscious imitation of the Olympians.

In other words, if Caligula really did have sex with his sisters, then it might not have been an act of depraved insanity, but rather a political maneuver that just didn’t work out the way he planned it to. (You may be sensing a bit of a theme here.)

ABOVE: Screenshot from the 1979 film Caligula of Caligula (played by Malcolm McDowell) with his sister Drusilla (played by Teresa Ann Savoy)

Seduced by Agrippina?

As we can see, it is unclear whether Caligula ever had sex with any of his sisters at all. Naturally, though, this has not stopped popular culture from inventing all kinds of stories about the alleged relationships between him and his sisters.

In the Netflix series Roman Empire: Caligula: The Mad Emperor, Caligula is portrayed as unwilling to engage in incest until his sister Agrippina actually comes to him in his bedchamber and seduces him, telling him that she will bear him a son who will serve as his heir. Caligula and Agrippina have sex for months, but she fails to become pregnant, so Caligula seduces first Drusilla and then Julia Livilla.

The way this is presented makes it seem like something that we know really happened and that is recorded in the ancient sources. In reality, it’s an entirely fictional scenario based on nothing but Suetonius’s claim that Caligula had sex with his sisters and the writers of the show’s awareness of Agrippina’s extraordinary cunning and domineering personality.

In fact, this scenario actually seems to contradict what Suetonius himself says in his Life of Caligula, since he makes it sound as though Drusilla was the first of Caligula’s sisters that he ever had sex with, not the second.

ABOVE: Screenshot from the Netflix series Roman Empire: Caligula: The Mad Emperor of Caligula being seduced by his sister Agrippina. There is no evidence that this ever happened.

Drusilla murdered?

In I, Claudius, episode nine (“Zeus, by Jove!”), Caligula is portrayed as impregnating Drusilla. Afterwards, he becomes increasingly paranoid, believing that the child developing in her womb will overthrow him and become the new king of the gods. Thus, at the end of the episode, he murders Drusilla, cuts open her womb, and devours the unborn child.

All of this is completely made up. Not only is it not found in any of the ancient sources, but it is not even found in the original 1934 novel I, Claudius by Robert Graves that the series is based on. In Graves’s original novel, Claudius merely says that he suspects that Drusilla was murdered by Caligula. This suspicion is never confirmed.

There is nothing in any of the ancient sources to indicate that Drusilla was murdered. Instead, the sources indicate that she died of a natural illness and that Caligula was genuinely devastated by her death. The only reason why Caligula murders her and devours her fetus in the show is because the writers of the show wanted to show the sheer extent of Caligula’s alleged insanity.

ABOVE: Screenshot from the I, Claudius episode “Zeus, By Jove!” of Caligula (played by John Hurt), dressed as Zeus, coming out of the room with blood all over his lips after eating Drusilla’s fetus

The emperor’s brothel?

In I, Claudius, episode ten (“Hail Who?”), Caligula turns the imperial palace into a brothel, where he pimps the wives of wealthy senators to the highest bidders. His uncle Claudius regards this whole situation as a disgrace, so Caligula forces him to collect money at the door.

This portrayal is based on what Suetonius says in his Life of Caligula, chapter 41. He writes, in Rolfe’s translation:

“To leave no kind of plunder untried, he opened a brothel in his palace, setting apart a number of rooms and furnishing them to suit the grandeur of the place, where matrons and freeborn youths should stand exposed. Then he sent his pages about the fora and basilicas, to invite young men and old to enjoy themselves, lending money on interest to those who came and having clerks openly take down their names, as contributors to Caesar’s revenues.”

Suetonius’s claim that Caligula turned a portion of the palace into a brothel, however, is not supported by any earlier sources and it represents exactly the sort of story some senator might have made up just to show how depraved the emperor was. Although prostitution was legal in the Roman Empire, prostitutes and pimps alike were widely looked down upon as lower-class scum. For the emperor, a man of the highest possible office, to literally act as a pimp would have been the utmost scandal.

Suetonius also claims that Caligula pimped his own sisters Agrippina and Julia Livilla, but, once again, there is no earlier evidence to substantiate this and it seems like the sort of thing a disgruntled senator would make up to discredit the emperor.

We can’t definitively say that Caligula did not turn the palace into a brothel and pimp his sisters to wealthy men, but it is probably a good idea to be skeptical of such stories. Furthermore, even if Caligula really did do these things, this wouldn’t necessarily make him insane, since a person does not have to be insane to be a pimp.

Indeed, Suetonius does give a rational explanation for why Caligula supposedly openly his brothel; according to Suetonius he did it because he was desperate for money to fund his outlandish lifestyle.

ABOVE: The Romans in their Decadence, painted in 1847 by the French Neoclassical painter Thomas Couture

The so-called “Plot of the Three Daggers”

The last part of the third episode of Roman Empire: Caligula: The Mad Emperor focuses extensively on the so-called “Plot of the Three Daggers,” which it turns into a elaborate conspiracy by Agrippina, Julia Livilla, and Aemilus Lepidus to murder Caligula and seize the throne.

In the show, Agrippina is supposed to lure Caligula into a bedroom so that the other conspirators can murder him, but, instead, she double crosses them, alerting Caligula to the conspiracy and leading him in with a troop of armed guards. Caligula then double crosses Agrippina by having her exiled along with the other conspirators.

Unfortunately, virtually everything the show says about the so-called “Plot of the Three Daggers” is completely made up. Basically all we really know about the supposed plot is that Agrippina, Julia Livilla, and Aemilius Lepidus were accused of adultery and conspiracy, Lepidus was executed, and the emperor’s sisters were sent into exile. Suetonius describes the entire alleged plot in just one sentence in his Life of Caligula, chapter 24:

“The rest of his sisters [i.e. Agrippina and Julia Livilla] he did not love with so great affection, nor honour so highly, but often prostituted them to his favourites; so that he was the readier at the trial of Aemilius Lepidus to condemn them, as adulteresses and privy to the conspiracies against him; and he not only made public letters in the handwriting of all of them, procured by fraud and seduction, but also dedicated to Mars the Avenger, with an explanatory inscription, three swords designed to take his life.”

The later historian Kassios Dion gives us a little bit more information about the alleged plot, writing in his Roman History 59.22.6–7, as translated by Earnest Cary:

“Another of his victims was Lepidus, that lover and favourite of his, the husband of Drusilla, the man who had together with Gaius maintained improper relations with the emperor’s other sisters, Agrippina and Julia, the man whom he had allowed to stand for office five years earlier than was permitted by law and whom he kept declaring he would leave as his successor to the throne. To celebrate this man’s death he gave the soldiers money, as though he had defeated some enemies, and sent three daggers to Mars Ultor in Rome.”

“He deported his sisters to the Pontian Islands because of their relations with Lepidus, having first accused them in a communication to the senate of many impious and immoral actions. Agrippina was given Lepidus’ bones in an urn and bidden to carry it back to Rome, keeping it in her bosom during the whole journey. Also, since many honours had been voted earlier to his sisters manifestly on his act, he forbade the awarding of other distinctions to any of his relatives.”

This is basically all the information we find about the so-called “Plot of the Three Daggers” in the ancient sources.

Notice that Suetonius seems to doubt that there was ever a conspiracy among Caligula’s sisters at all and instead seems to believe that Caligula just made the whole thing up as an excuse to send his sisters into exile. The only reason why the supposed conspiracy occupies such a pride of place in the Netflix series is because the makers of the series are desperate to spice things up with a little intrigue.

ABOVE: Screenshot of Agrippina, Julia Livilla, and Aemilus Lepidus coming up with the so-called “Plot of the Three Daggers,” as portrayed in the Netflix series Roman Empire: Caligula: The Mad Emperor

Caligula’s profligacy

Suetonius spends a lot of time in his Life of Caligula ranting about the emperor’s profligacy. In chapter 37, he famously writes:

“In reckless extravagance he outdid the prodigals of all times in ingenuity, inventing a new sort of baths and unnatural varieties of food and feasts; for he would bathe in hot or cold perfumed oils, drink pearls of great price dissolved in vinegar, and set before his guests loaves and meats of gold, declaring that a man ought either to be frugal or Caesar. He even scattered large sums of money among the commons from the roof of the basilica Julia for several days in succession.”

It’s almost certainly true that Caligula was a profligate spender, but the extent of his profligacy as reported by Suetonius is probably greatly exaggerated. Ancient Roman writers often focus on profligate spending as an indication that a ruler is foolish and morally degenerate. Thus, when Suetonius talks about Caligula wasting money, the point is to convey that he was a bad emperor.

The claim that Caligula drank “pearls of great price dissolved in vinegar” is especially suspect because it is a standard canard that the Romans often told about anyone they didn’t like. The story first appears in Horace’s Satires 2.3.239–42, in which the person who dissolves and drinks the expensive pearls is the unnamed son of the famous orator Aesopus. Another version of the story is told by Pliny the Elder in his Natural History 9.58, but this time the pearl-dissolver is none other than the famous Queen Cleopatra VII Philopator of Egypt.

In each iteration of the story, all that changes is the person who is doing the pearl-dissolving. Essentially, Suetonius is recycling an age-old folktale about profligacy and turning it into a story about Caligula.

ABOVE: The Banquet of Cleopatra, painted in 1653 by the Flemish painter Jacob Jordaens. The exact same story is told about both Cleopatra and Caligula and, in all likelihood, never happened with either of them.

Seeing an emperor about a horse

Probably the most famous story about Caligula is the one about how he supposedly made his horse Incitatus a senator. This certainly never happened and there are no surviving ancient sources that say he actually did this. Suetonius does, however, claim that Caligula lavished an unusual amount of attention on Incitatus and that he was alleged to have talked about making him a consul. Suetonius writes in his Life of Caligula 55, as translated by Rolfe:

“He used to send his soldiers on the day before the games and order silence in the neighbourhood, to prevent the horse Incitatus from being disturbed. Besides a stall of marble, a manger of ivory, purple blankets and a collar of precious stones, he even gave this horse a house, a troop of slaves and furniture, for the more elegant entertainment of the guests invited in his name; and it is also said that he planned to make him consul.”

Notice that, in Suetonius’s version, making his horse consul is only something that Caligula talked about doing, not something he ever actually did.

The story about Caligula allegedly planning to make Incitatus a consul also appears in Kassios Dion’s Roman History 59.14.7. Dion writes, as translated by Earnest Cary:

“One of the horses, which he named Incitatus, he used to invite to dinner, where he would offer him golden barley and drink his health in wine from golden goblets; he swore by the animal’s life and fortune and even promised to appoint him consul, a promise that he would certainly have carried out if he had lived longer.”

Dion was writing around a hundred years after Suetonius, however, and most likely used Suetonius’s Life of Caligula as a source, so he probably can’t be considered an independent witness.

ABOVE: Screenshot of Caligula (played by John Hurt) with his horse Incitatus from the 1976 television series I, Claudius

All we really have to support this story is Suetonius’s word, which, frankly, isn’t worth a whole lot, especially since Suetonius seems unsure about the story’s veracity himself. It is entirely possible that this whole account about Caligula planning to make his horse a consul is fabricated. Even if the story is true, there are still a couple different ways we can interpret it that don’t entail Caligula being completely bonkers.

The first interpretation is that Caligula really did shower attention on his horse and talk about making him consul, but it was all an elaborate mockery of the Senate. As I’ve noted a few times already, one of the best-attested facts about Caligula’s reign is that he held the Senate in total disdain. It’s possible that he may have joked about making his horse consul, with the implication that the people who actually were serving as consuls were so terrible that even a horse could do the job better than them.

The second interpretation is that Caligula really did lavish attention on Incitatus, but that he didn’t really have plans to make him a consul. In the same way that some people today lavish attention on their dogs, it is easy to see how Caligula might lavish attention on his horse. It is also easy to see how senators might have gotten annoyed by Caligula paying so much attention to his horse while treating the Senate with disdain and therefore started joking about how Caligula loved his horse so much that he was probably planning to make him a consul.

ABOVE: Photograph of a Roman marble sculpture in the British Museum depicting a nude young man riding on horseback, widely suspected to represent the notorious emperor Caligula on his horse Incitatus

The alleged “war on Neptune”

Another famous story holds that Caligula was so crazy that he once declared war on Neptune and made his soldiers attack the sea and then gather seashells as “loot.” This story originates from what Suetonius writes in his Life of Caligula 46:

“Finally, as if he intended to bring the war to an end, he drew up a line of battle on the shore of the Ocean, arranging his ballistas and other artillery; and when no one knew or could imagine what he was going to do, he suddenly bade them gather shells and fill their helmets and the folds of their gowns, calling them ‘spoils from the Ocean, due to the Capitol and Palatine.’”

There are no sources earlier than Suetonius that mention anything about this alleged incident and it is entirely possible that Suetonius may have just made it up. If there is any truth to the story, it is possible that Caligula may have intended this as a humiliating punishment for his soldiers, who, according to Suetonius himself, had just been on the brink of mutiny. The idea behind it may have been that, because they had made him feel foolish on his campaign, he would make them feel foolish as well.

ABOVE: Screenshot of Caligula’s soldiers pouring out the “loot from old Neptune” in the 1976 television series I, Claudius

Caligula’s murder

The ancient Roman historical sources record that Caligula was assassinated by members of a conspiracy led by a man named Cassius Chaerea on 24 January 41 AD while he was passing through a narrow covered passage. Afterwards, the assassins murdered his wife Milonia Caesonia and their one-year-old daughter Julia Drusilla.

Caligula’s uncle Claudius supposedly hid from the assassins behind a curtain in the imperial palace until he was discovered by loyal members of the Praetorian Guard, who escorted him to their camp, where they proclaimed him emperor. It is unclear why the Praetorian Guard declared Claudius emperor, but it is possible that they may have believed that he was feeble-minded and that he would be easy to control.

As usual, though, the Netflix series Roman Empire: Caligula: The Mad Emperor is absolutely desperate for something juicier. For them, a conspiracy and an assassination isn’t enough; Claudius has to be in on it all too. Thus, in the series, Claudius is not only portrayed as the real mastermind behind Caligula’s murder, but as being present at the scene of the crime itself. In the show, the soldier who stabs Caligula immediately turns around to pledge his undying loyalty to Claudius.

There is very little evidence to support the idea that Claudius had anything to do with Caligula’s assassination. Regardless of whether or not he was involved, though, he was certainly not standing there when Caligula was actually murdered. None of the ancient sources claim that he was there and we know that, throughout his reign, he was not perceived as having had anything to do with Caligula’s assassination. If he had been there when Caligula was murdered, it’s hard to see how he could have possibly kept his image so clean.

It is also worth noting that Caligula wasn’t just stabbed once by a single soldier; the ancient sources record that he was stabbed repeatedly by several different conspirators. They even draw explicit comparisons to the murder of Julius Caesar.

ABOVE: Proclaiming Claudius Emperor, painted in 1867 by the Dutch painter Lawrence Alma-Tadema

Conclusion

Putting all of these stories aside, the contemporary sources do unambiguously claim that Caligula was insane. Philon asserts in his Embassy to Gaius, chapter thirteen, that Caligula gave in to “madness and frenzy” and that he was “utterly insane.” Seneca exclaims with regard to Caligula in his On Anger 1.20, “How great was his madness!” Suetonius claims in his Life of Caligula, chapter fifty, “He was sound neither of body nor mind.”

Nonetheless, we should take all these descriptions with a grain of salt, since all of these sources are biased and it is common for people to describe political leaders they don’t like as insane, even though those leaders rarely ever meet the clinical definition of insanity. Indeed, I think I myself have described Donald Trump as insane more than once, but yet I don’t think he would meet the clinical definition of insanity and I don’t think Caligula would either.