Ah, Caligula.  In recent times, historians have been revisiting the life and times of this controversial Roman emperor, trying to make some sort of narrative that might help rehabilitate his tarnished image.  Honestly, I cannot conceive of a universe wherein this would be possible.

If the picture on the right is anything close to reality, then this guy isn't really a looker.  

When I was about 13, Masterpiece Theater ran a series starring Derek Jacobi called "I Claudius."  It was based on a duology about the life of Claudius, sort of a grandson to emperor Augustus.  When it came to depicting the life of Caligula, well, let's just say it was less than complimentary.

you just gotta check this one out.

Did you watch it? Are you laughing uproariously? Me too.

 Alright.  Let the bloody carnival begin....

In terms of actual primary sources about this psycho’s reign, there are few. We have Suetonius, for sure.  There is also Josephus.  Both depict Gaius as an enraged, brutal, vulgarian. But, was he? Well, the dilemma about this guy, for historians of ancient imperial Rome, is whether or not the aforementioned sources are anything close to accurate, or a deliberate (and perhaps malicious) distortion of the facts.  Perhaps the truth lies in an orbit around the planet Neptune.  From what I’ve been able to understand about this mad man, he wasn’t misunderstood at all, and any rehabilitation of his life and “legacy” is a questionable action by modern scholars.  At any rate, until I see new irrefutable sources, I'm gonna follow my own instincts, and accept traditional interpretations of "Little Gaius."

Caligula was the son of Germanicus (a celebrated general) and Agrippina the Elder.  As the emperor Tiberius neared the end of his life, he appointed Caligula his heir, along with his grandson.  Upon the emperor's' death, young Gaius ascended, and the young grandson shunted to the side.  I guess you know what happened to that poor kid, Dear Reader.

Caligula was 25, and the year was 12 CE.

Suetonius has something interesting to say regarding the death of Tiberius:

        Some think that Gaius gave him a slow and wasting poison; others that during convalescence from an attack of fever food was refused him when he asked for it. Some say that a pillow was thrown    upon his face, when he came to and asked for a ring which had been taken from him during a fainting  p399 fit. Seneca writes that conscious ofapproaching end, he took off the ring, as if to give it to someone, but held fast to it for a time; then he put it back on his finger, and clenching his left hand, lay for a long time motionless; suddenly he called for his attendants, and on receiving no response, got up; but his strength failed him and he fell dead near the couch.

                                                                Suetonius, The Twelve Caesars, Tiberius

Upon taking the center seat, Caligula seemed quite promising.  Indeed, the people of Rome rejoiced to have a son by the noble Germanicus as emperor.  Among other things, Caligula set to erasing some of the wrongs done during the reign of Tiberius, such as pardoning those who had been erroneously arrested for treason, malicious comments about the emperor, and flying to the moon.  Apparently, there was little or no truth in any of these charges.  He also indulged in staging games in the city's arena, which greatly pleased the populace.

The new young emperor wasn't a GQ cover boy, by all reports.  Here's what Suetonius reports about Gaius' physical traits:

Height: tall.

Complexion: pallid.

Body: hairy and badly built.

Neck: thin.

Legs: spindling.

Eyes and temples: hollow.

Forehead: broad and forbidding.

Scalp: almost hairless, especially on the top.

https://facultystaff.richmond.edu/~wstevens/history331texts/caligula.html

In October of the same year he took the throne, Caligula apparently became seriously ill.  Some called it brain fever, but no contemporary doctor was able to give a definitive diagnosis.  What historians tell us, is that Caligula entered into a coma, where he lingered on the edge of death for many days.  In 2021, Jesus David Chary Sanchez, et al, proposed several viable explanations for Caligula's condition:  Encephalitis, lead poisoning, Neurosyphilis, and Epilepsy.  This last disease may be the likeliest candidate, but we'll never really know.  Here's what the authors say about the 'symptoms' of epilepsy, which may indeed be consistent with descriptions of the new emperor's sickness:

It has been suggested that members of the Julius family suffered from epilepsy. Additionally, several historians point out that, during his childhood, Caligula had episodes of sudden falls in which he lost consciousness and had difficulty remaining upright.  Analyzed from a modern perspective, these episodes may indicate atonic seizures....After this episode, he showed constant mood swings with irascibility or unmotivated laughter, lack of impulse control, perverse behaviors, hypersexuality, and sadism, and was terrified by thunder and loud noises. Caligula also suffered from severe insomnia and could not sleep more than three hours per night. Furthermore, he experienced delusions of grandeur, paranoid episodes, and strange behaviors, such as when he ordered his troops to collect seashells from the shore    

                                                            https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9231447/

Yeah, that’s right:  seashells.

Unfortunately for Rome, he survived.  Records indicate, that Caligula's behavior changed radically in the aftermath of his coma.  He became capricious, blood thirsty, and cruel.  So much so, that people began to think him a madman.  What follows are some of the rumors that circulated about his conduct:

Mr. Ed, a.k.a. Incitatus:

No, you're not hallucinating, that is a horse at the dinner table.

“Urban” legends first, Dear Reader.  Let us take Incitatus first.  Did Caligula did he house a famous and victorious chariot horse in a golden stable (according to Suetonius), and feed him food mixed with gold?  Well, yes, as far as we can tell from existing sources.  A favorite story about Incitatus, is that he made it a Consul of Rome--one of the highest magistracies in the Roman state.  Was this true? To tell you the truth, we don't know:  it could be a derogatory rumor distributed by later historians Suetonius, and Cassius Dio.  For example, the former wrote:  

            …it is also reported that he designated [Incitatus] to the consulship. 

Whereas Dio stated:

        he even promised to designate [Incitatus] consul. And he would most certainly have         done this, if he had lived longer.

Honestly, that's pretty much it in terms of 'proof' about this mad action.  But, it sure makes a good story. As to the 'truth'? Who knows.   

Note:  I must warn you about Suetonius:  most classicists refer to him as a gossip monger, rather than a reliable historian reinterpreting the past.  But, I'm not sure that I entirely agree with this:  I think that there is a grain of truth hidden amidst the sand.  As always, you should come to your own conclusions, Dear Reader.

Another tale about Caligula, is that he committed incest with all of his sisters, perhaps even treating his favorite sister, Julia Drucilla as his wife.

About Drucilla;

In 33, Drusilla was married to Lucius Cassius Longinus, who was a friend of Tiberius--the successor to Augustus.  It is not established that the couple had any children.^[a] After becoming emperor in 37, Gaius (Caligula) ordered Julia Drucilla to divorce Longinus, and marry his chum Marcus Aemilius Lepidus.  This was a fairly common practice--using and breeding women like sheep in a herd.  Quite simply (although they might have plenty to say about it), aristocratic Roman women went where they were sent by the men in their families.

Classicists are fairly content with the notion that brother and sister were extremely close--they were often seen in public being affectionate with one another, and Caligula gave Drucilla honors one might give to a wife or lover.  However there is no irrefutable evidence suggesting an incestuous relationship.

We have a series of known instances where Caligula clearly favored Drucilla above his other sisters, and other women.  For example, at royal banquets, as the emperor was a bachelor, it was customary for his sisters to help preside over meals.  Each sister would take turns on different days:  this was an established custom.  I cannot stress too much the importance Romans placed on social traditions.  Caligula did away with this practice, however, and instead had Drucilla host his banquets everyday.

I know what you may be thinking:  so effing what? All I can say, is that its' interesting, perhaps even suggestive.

Here another interesting fact:  when writing his will, Caligula made Drucilla his heir.  To name a woman thus was extremely rare.

And, that's about all we have in the 'reliable' historical record.

Rumors of incest were boldly stated by Suetonius, some 28 years after Caligula's death:

        It is believed, that he deflowered one of them, Drusilla, before he had assumed the robe of manhood; and was even caught in her embraces by his grandmother Antonia

                                                                                    Suetonius, Caligula, 24.

Suetonius also alleges that Caligula had sex with all his sisters. But, the quote I've given you here is pretty much it.  Emphasis on the phrase 'pretty much.' As to the truth? My previous comment stands.

Frankly, Dear Reader, there are many, many stories about Caligula's reign of terror, but which ones are true or false, who the hell knows? However, even these stories may indicate something of his altered character, in the wake of his coma.  What historians mostly agree upon, is that his public behavior became erratic, even frightening after his illness.  Was this an illness-driven psychosis? We cannot know for sure, particularly at this late date.  I'm going to recommend this documentary--it's rather good, I think--but then anything with Mary Beard (or Lucy Worsley, for that matter) is excellent: