The Caligula



"''"Madness reigns In the hall of the Mountain King""

- Savatage, "Hall of the Mountain King"

The downside of any hereditary monarchy is that every so often the throne is inherited by someone completely out of his gourd. It could be the lead plumbing (or complete lack thereof), the immortality elixirs (which all make use of mercury) or it's genetic (in which case you're in some deep trouble). Yet, despite the sovereign's obvious insanity, he is still given the full power and support of the State, with inevitably disastrous consequences.

The Caligula will be wildly irrational, violently moody, very intolerant of being told anything he doesn't want to hear, and probably afflicted with a god complex. He may indulge in renaming cities or even the entire country after himself. To do anything the Caligula finds displeasing is to inevitably be dragged off to a grisly death or worse. Of course, this could also happen to those who have not done anything at all. Due to their continuing close proximity to the Caligula, members of the Court (decadent or otherwise) will be the primary targets of his fits of rage. The Caligula is very definitely a Bad Boss. With any luck, thanks to The Starscream/Reliable Traitor/La Résistance, a conspiracy will eventually develop to remove the crazy sovereign from his post... permanently.

And while all of this is going on, the land over which the Caligula rules is rapidly going down the drain due to his neglect. At best. If he's a Glory Hound, he has an advantage over most: he can start wars.

This is not limited to sovereign heads of state. The Caligula can be anyone wielding great power within an organization while being completely nuts. Modern psychology has shown that the corporate business structure, if emphasizing financial profit to the detriment of anything else, can be especially prone to the appearances of individuals displaying at least a majority if not all of The Caligula's traits (so long as the person seeking profits is a psychopath at least, which is what the book seems to be saying.)

See Royally Screwed-Up for when the this type of character becomes a recurring family problem. Also see President Evil for when this guy is actually voted into office

The canonical alignment for many Caligulas is Chaotic Evil of the Type 4 variety, though some Neutral Evil examples exist. Lawful Evil Caligulas are possible (though rare enough to be almost unheard of) as any alignment is subject to insanity and Lawful Evil characters do enjoy establishing cruel laws and seeing their minions enforce them.

Named for what is probably history's best known whack-job, Roman emperor Gaius Julius Caesar Augustus Germanicus, better known as Caligula (Little Boots, his childhood nickname), a reference to the child-sized "caliga" warrior's sandals he wore as a small child when his father took him to watch a war; remembered for talking to statues, locking granaries, declaring war on Poseidon (and "winning" and commanding his soldiers to collect seashells as war-prizes), making his horse a consul, and boning his sisters.

In terms of the ranks of Authority Tropes, the tropes that are equal are The Good Chancellor, Evil Chancellor, Standard Royal Court and Deadly Decadent Court. The next step down is The Brigadier. The next steps up are The Evil Prince, Prince Charming, Prince Charmless, Warrior Prince, The White Prince, The Wise Prince, and all Princess Tropes.

So what does it take to be the Trope Namer for insane royalty? The Emperor Caligula page has the details.

Anime & Manga

 * Queen Himiko from the Dawn arc of Phoenix, who then dooms her kingdom by exiling her Brother when he finally tells her enough is enough.
 * The Maestro Delphine of Last Exile.
 * King Hamdo of Now and Then Here and There is a petty, raging tyrant who expends his armies of enslaved Child Soldiers at will. His first scenes involve strangling his cat when it upsets him, and then having the child protagonist tortured for hours and hours on end.
 * Niwe of Utawarerumono.
 * Emperor Ganishka in the latest arc of Berserk, who even manages to stand head and shoulders above the other villains in the series. No small feat, considering they were nearly all absolutely horrible Complete Monsters.
 * Fruits Basket: While not actually royalty, Akito plays this role as head of the Sohma family.
 * The World Government of One Piece appears to fall into this, although not the Marines protecting it. The World Government itself is incredibly corrupt and brutal, being major patrons of the mostly pirate-run slave trade and using the Marines for acts of mass butchery to silence those that found out their dirty secrets or could threaten them. The nobility of this world is even worse, as the upper-middle class will cheerfully burn an occupied city to the ground to make things look neater for a World Noble's visit and claim it's the poor people's fault for being too stupid to be born nobles. The highest social class are so batshit insane they wear air bubbles to prevent themselves from breathing the same air as commoners and regularly murder anyone they encounter them over the very pettiest gripes.
 * Were he to achieve his goal of taking over Fishman Island, Hodi Jones would easily be this - his immediate plans would be to slaughter anyone on the island who wants to live in peace with humans, followed by going to a council of kings with the intended purpose of murdering them all.
 * Kirby of the Stars, King Dedede has a castle which has his face all over the place, the only thing he ever does is find ways to take advantage of the cappies, and orders monsters from the truly nightmarish evil corporation to make everyone miserable, or just to beat Kirby.
 * Clair Leonelli of Heat Guy J. This (more than the fact that he's only 19 years old) is the reason the other Mafia higher-ups are reluctant to let him assume the role of Vampire.
 * Gihren Zabi of Mobile Suit Gundam, a soulless Evil Prince who has no problems murdering his father to seize power, using Weapons of Mass Destruction to butcher civillian populations, or subverting the entire war effort in the name of his Social Darwinist agenda. He's less overtly crazy than many examples, but makes up for it with his total Lack of Empathy and emotionless psychopathy.
 * Kano from Texhnolyze, the Big Bad. While very intelligent, charismatic and eloquent, he's a deranged solipsist who believes that he's the only real person in a world that exists inside his mind. A possible explanation for this may be the fact that he's the result of generations of selective inbreeding, designed to create the perfect ruler.

Comicbooks

 * Conan the Barbarian came up against mad and corrupt kings with some regularity, but the most notable of these was King Numedides, who Conan overthrew to become king of Aquilonia. Numedides regularly had men and women flayed alive for minor transgressions; indeed, when Conan was imprisoned in his tower, Numedides executed a dancer who Conan liked and ordered a scrap of her flesh tossed in Conan's cell. Conan immediately recognized whom it belonged to because of the dancer's many tattoos. As well, in order to become immortal, Numedides enlisted the services of the Evil Sorcerer Thulandra Thuu; together, they sacrificed young women in order for Numedides to bathe in their blood.
 * In "The Hour of the Dragon," Valerius fits this trope perfectly: his drunken revelry, sexual violence and senseless slaughter was so extensive that his co-conspirators had to step in, to stop him from running the kingdom into the ground.
 * In Robert E. Howard's original story, Valerius does this deliberately, in order to ruin the realm, because he knows You Have Outlived Your Usefulness is coming, and wants Taking You with Me so his co-conspirators won't profit.
 * Chief Judge Cal in the Judge Dredd story "The Day The Law Died" (collected as Judge Caligula) is, as the name suggests, closely based on the Emperor (even being drawn to resemble John Hurt in I, Claudius). Caligula (allegedly) made his horse a senator; Cal made his goldfish Deputy Chief Judge. Caligula demanded grandiose building projects; Cal expected the citizens to build a mile high wall around Mega-City One in a week. He also argued with deceased former Chief Judges, preserved his execution victims in vinegar, and sentenced the entire city to death twice. At least the mile-high wall actually helped protect the city later on.
 * Vulcan (from the Summers' Tangled Family Tree) becomes king of the Shi'ar empire, of all things, and essentially drives the entire people to hell, dividing them and thus starting the War of Kings.
 * Former Shi'ar king D'Ken, who is at least partially responsible for Vulcan being as screwed up as he is, was another fine example (until he was killed by, you guessed it, Vulcan).
 * Like Conan, Red Sonja has come up against her fair share of mad kings. Unlike Conan, most of them attempted to imprison her in their harems. Bad move.
 * Two-Spear in Elf Quest. Winnowill, too.
 * King Kel in Strontium Dog
 * The Red King, main villain of the Planet Hulk storyline, fits this trope to a T.
 * In the Dark Empire arc of the Star Wars comic lines, Palpatine became this after his first resurrection. Although he was definitely not a good person prior to his first death in Return of the Jedi, he at least was sane enough to actually succeed in his plans and manipulate factors in his favor. Afterwards, he's become just yet another insane, megalomaniacal tyrant (his increased insanity was heavily implied to be the direct result of transferring his spirit into clones.)
 * It also probably didn't help that.
 * The Yellow Bastard would have been this if he was able to inhherit his family's political power. He was an insane, violent, sexual deviant who preyed on kids... and was being groomed as a future US president before he met his end.

Film
""From this day on, the official language of San Marcos will be Swedish. In addition to that, all citizens will be required to change their underwear every half-hour. Underwear will be worn on the outside so we can check. Furthermore, all children under 16 years old are now... 16 years old!""
 * Of course, there is Caligula himself, who appears in the guise of Jay Robinson in The Robe (1953), of John Hurt in I, Claudius (1976) and Demetrius and The Gladiators (1954) and of Malcolm McDowell in (what else?) Caligula (1979).
 * The Roman Emperor Commodus as depicted in Gladiator and The Fall Of The Roman Empire. Commodus wasn't as bad in real life as he was in either film, but he still wasn't the sort of monarch you'd take home to mother -- he once walked into the Senate with a severed ostrich head, fought as a gladiator in the arena (against disabled opponents who stood no chance), and is best-known for ending the "Five Good Emperors".
 * The portrayal of Idi Amin in The Last King of Scotland exemplifies this trope almost perfectly. He begins as an Anti-Hero and descends into complete madness and insanity.
 * Harold Shand, anti-hero of the classic 1980 British gangster movie The Long Good Friday. He begins as a competent mob boss with grand ambitions, who nonetheless seems sane and grounded. After a series of mysterious and violent incidents chip away at his criminal empire, he gradually falls apart; by the end of the film he has slit the throat of his most trusted lieutenant, alienated his most valuable business partners, and had his fellow gang bosses strung up on meat hooks. It all ends badly.
 * Roberto is depicted as one in Futurama: Bender's Game, having sent his entire army out to wage war on scallops, but sunk the ships wiping them out.
 * Swan, the villainous record producer of Phantom of the Paradise. Though he styles himself as an Affably Evil manipulator, almost every single decision he makes in the film is made on a whim: his employees are hired, fired or reassigned on the flimsiest of reasons, he imprisons his stars in torturously ironclad contracts, rewrites the Phantom's music to cater to his own eccentric tastes, and even orders his fiancée assassinated at his wedding for the sake of publicity. Worse still, not only is he in complete control of the music industry,
 * Then there's Quo Vadis?, which gave us a delightfully mad Nero played by Peter Ustinov. Arguably one of the best things in the whole movie.
 * In the Woody Allen film Bananas, the rebel leader Esposito goes mad with power the second he gains control of San Marcos. For your consideration, his speech to the people of San Marcos:


 * The King of The King and the Clown is based on the Korean ruler Yeonsangun of Joseon. In the film he is ruthless and erratic in his behavior, but also very cultured and rather sympathetic at times, with loads of Freudian Excuse.
 * Komodo in the film Warriors of Virtue certainly qualifies.
 * Emperor Tod Spengo of Mom and Dad Save The World.
 * The Alternate Universe version of Biff Tannen in Back to The Future: Part II. Using the Gray's Sports Almanac he obtained from his future self, he wins an insane amount of money from gambling, which he uses to become mayor and buy off the police, turning Hill Valley into a Mad Max-styled city.
 * In 13 Assassins, Lord Naritsugu is the Shogun's little brother, and uses his position to do such depravities that his house's vassals start committing seppuku in protest. The main conflict of the movie is that the Shogun wants him killed without dishonouring their house.
 * Aedenoid Hynkel from The Great Dictator, a parody of Hitler who even dances with a globe of the world as he thinks of becoming 'Emperor of the World'.
 * Admiral General Aladeen from The Dictator. Among other things, the guy has his own men executed for the most trivial reasons such as his nuclear missile program head not having made the missile pointy or one of his men accidentally blocking him on a staircase, he hosted is own "Aladeen Games" where he won every single event (the one shown being a race where he shoots the other athletes in the leg and has the finishing line carried forward to break it) and even changed a large percentage of the words in the language in his country to "Aladeen"...including contradictory words like "positive/negative" and "open/closed", causing immense confusion. All Played for Laughs, naturally.

Literature
"Specifically, "If a horse's ass can be a Count, why not the whole horse?""
 * Caligula is a central character to the novel I, Claudius by Robert Graves, and he is as insane as you would think.
 * He declares himself a god, which he feels justifies
 * And when he actually becomes emperor... you'd better watch out.
 * A. E. van Vogt's EMPIRE OF THE ATOM and THE WIZARD OF LINN has most prominent characters as analogues of Roman history, starting with Clane/Claudius. "Calaj" is the obvious Caligula stand in, the grandson of Lydia/Livia and related to Clane and Tews/Tiberius.
 * The Prophet's House Quintology loves this trope, featuring the deranged twenty something dictator Anora, as well as her nephew/husband Anaias (who's even worse).
 * A Song of Ice and Fire gives us both King Aerys II "The Mad" Targaryen and King Joffrey Baratheon (who knew a 13-year-old could be that psychotic?). The former was the worst King that Westeros ever had, and a powerful 300-year old dynasty was overthrown because of his insane actions. The latter's reckless, childish cruelty and love of ordering executions resulted in a continent-wide civil war.
 * Indeed, the whole Targaryen dynasty had this trope going on. Half of them were either good or competent rulers. The other half were Caligulas, with Aerys merely being the one who took it too far. Of Aerys' children, his son Rhaeger and daughter Daenerys are sane, while his other son Viserys is the next Caligula-to-be. The dynastic tradition of Brother-Sister Incest might have had something to do with this.
 * There is Cersei as the Queen Regent, as well. Not as bad as her son Joffrey, though.
 * Swemmel, king of Unkerlant, in Harry Turtledove's Darkness novels, who's really just a Fantasy Counterpart Culture equivalent of Joseph Stalin.
 * The "Gentleman With the Thistle-down Hair" from Jonathan Strange and Mr. Norrell both in his dealings with humans and management of his kingdom in Faerie. Which is, admittedly, pretty common among faeries.
 * Discworld throws a few examples at us:
 * There was King Gurnt the Stupid of Lancre, whose attempt at training an aerial attack force of armored ravens never got off the ground.
 * Duke Felmet, also of Lancre, might have been stable before he gained the throne through regicide, but afterwards he would regularly try to remove the blood from his hands via sandpaper or cheese grater and be surprised that this only generated more.
 * His wife is even worse, being nothing more than a card carrying Social Darwinist sociopath.
 * Ankh-Morpork has had its share of unbalanced rulers as well, like King Ludwig the Tree, who once issued a royal proclamation on the need to develop a new type of frog and thought up the city motto "Quanti Canicula Ille In Fenestra" (which is pseudo-Latin for "How much is that doggy in the window?"), and King Lorenzo the Kind, who was "very fond of children". King Lorenzo was the last straw; after his execution, Ankh-Morpork became a republic, led by the Patrician -- although actually it was more like the nobles appointed one of their number to wield power. By the time of the books, the Council chooses the Patrician and includes nobles and Guild leaders. Safe to say there is no electing in the modern sense going on. Mind you, some of the Patricians weren't much better:
 * Homicidal Lord Winder turned Ankh-Morpork into a police state out of paranoia.
 * The aptly named Psychoneurotic (sometimes merely Mad) Lord Snapcase -- who, in a Shout-Out to Caligula, made his horse a councilor. (Although it apparently wasn't a bad one compared to the others: a vase, a heap of sand, and three people who had been beheaded.)
 * Yet another example is the Agatean Emperor in Interesting Times, who is liable to order people tortured to death or rewarded based upon the slightest whim (since no one ever dared to tell him that this is wrong).
 * Lois McMaster Bujold's Barrayaran Empire had a Mad Emperor Yuri about a generation before the Vorkosigan series starts.
 * They've also had Prince Serg, who would certainly have qualified, had he not... conveniently died... before succeeding to the throne.
 * Also, there is a widely-mentioned historical case where a Count Vortala did appoint his horse, Midnight, as his heir, but there is no indication that Vortala was either crazy, or evil. He just did it as a Take That to his previous heir, whom he was having an argument with.


 * Mad King Alan II in Stephen King's The Eyes of the Dragon is a good example of this, although his madness tended more towards harmless debauchery. It was only through the malevolent influence of the story's Big Bad that he inflicted genuine suffering on the populace.
 * The Queen of Hearts in Alice in Wonderland, arguably. Adaptations have played it up even more.
 * Several of the gods portrayed in the series Everworld fit this description perfectly. Almost every god that the main characters encounter, regardless of what mythology they originate from, has an utterly apathetic regard for life in general (being gods and all) and shows a certain degree of sadism, though some of them (especially Neptune) are simply bat-shit insane.
 * The Harkonnens in Frank Herbert's Dune novels were pretty much an entire family of Caligulas. Gladiatorial death sports, hunting humans as game, Perverse Sexual Lust, murdering random servants, obscenely expensive luxuries, drug addiction, torture as entertainment--they did it all.
 * The ruling Urga line of Cthol Murgos in the Belgariad all reliably go insane before late middle age. Taur Urgas is said to execute people for stepping on his shadow and encourages his sons to kill each other so the strongest one could claim the throne; when the king of Algaria kills him, he turns completely animalistic in his death throes. Urgit, his successor in the Mallorean, survived to that point by stealing a key to the treasury and hiring assassins; he's actually sane, if a Deadpan Snarker, but that's because
 * Urgit does seem a bit unstable at first, though more flippant than bloodthirsty, but that is because he is very well aware of the 'all reliably go insane before late middle age' rule. If you know you'll descend into insanity soon enough, why bother? As soon as he learns why his mother is so insistent the Urga curse won't affect him, he quickly drops the flippancy and becomes an effective ruler.
 * King Ademar of Gorhaut in Guy Gavriel Kay's A Song for Arbonne has rabid dogs tearing each other to pieces before the throne and maids give him blowjobs right in front of a very discomfitted court, among many other strange hobbies.
 * At least as portrayed in the 1632 series, Charles I of England seems to qualify. The Stuart monarchs in general were firm believers in the divine right of kings; they were also generally pretty feckless as rulers. 1632 Charles has heard what will happen to him and is lashing out at his future enemies. True to form, he's messing it up (he's driven his historical best supporter into working with Cromwell, who's still alive, if on the run). Odds are the English Civil will come early in this world. This makes him a particularly incompetent Caligula.
 * The 120 Days of Sodom by the Marquis de Sade centers around four French aristocrats who use their vast wealth and power to have sixteen young teenagers kidnapped. They lock themselves in a secluded castle with those teenagers, their own daughters, four old prostitutes, eight massively endowed men, and the four ugliest old women they can find. Over the next four months, they have the "ultimate in orgies" - they rape, torture, dismember, and murder all but a few of those guests. The film adaptation of this story, which replaces the aristocrats with Italian Fascists, is widely regarded to be one of the most sickening films ever made.
 * In Barry Hughart's The Story of the Stone, the infamous Laughing Prince committed all sorts of horrors on the peasants in his valley, some of them in pursuit of immortality, some just because he was crazy. He was named for his cheerful, laughing demeanor and charming little dance step. Li Kao diagnoses him as brain-damaged from repeated consumption of a mercury-laced "elixir of life."
 * Meet High Lord Kalarus: exploited his people for every speck of wealth, perfected discipline collars, tried to overthrow the First Lord by allying with Alera's oldest enemies, and when that failed, tried to take the entire country with him. Not a nice guy, and a few legionnaires short of a cohort.
 * Randall Flagg from The Stand barely remembers most of his own life, is prone to childish fits of anger, and doesn't even seem to understand his own motivations; he just seems driven by some instinct or outside force to cause as much mayhem and destruction as he possibly can. And he may or may not be the devil.
 * In Robert E. Howard's Conan the Barbarian story "A Witch Shall Be Born", Tamaris's subjects think she's gone mad after Salome pulls off a Fake King.
 * Astrabolo in Stationery Voyagers. There is no dog (or its cousin) he won't kick.
 * Autarch Sulepis of Shadowmarch has it all- bizarre behavior, tyrannical style of rule, unhealthy fondness for recreational inflicting of pain and designs on godhood
 * The Crackling Prince in Walter Jon Williams ARISTOI probably qualifies, although he never appears and is referred to only in discussing the past. He planned on "artistically" reconfiguring planetary landscapes with gravity generators --- with the people still living on them and expected to be grateful. Understandably "a commission had been formed in Perseopolis to examine his behavior", but he was somehow persuaded to retire before the other Aristoi actually did anything.
 * Vlad Tepes in Count and Countess, though he will try to tell you otherwise.

Live-Action TV

 * The Emperor Caligula himself, as magnificently depicted by John Hurt in I, Claudius. (See also Brother-Sister Incest.)
 * The Centauri Republic's insane emperor Cartagia from Babylon 5. He even sets his planet on a path he knows will probably end with it because he thinks it'll make a fitting ceremony for his ascension to godhood.
 * Peter Falk plays a thinly-disguised Expy of Fidel Castro in an episode of the original Twilight Zone that revolts against the previous ruler. Once in power, he becomes insanely paranoid and orders the executions of all of his former allies because he thinks they want to assassinate him. He finally flips out completely and commits suicide.
 * Monica Mancuso on Las Vegas. The Montecito’s other owners have ranged from reasonable (Gavin Brunson) to friendly (Casey Manning) to aloof but thoughtful (AJ Cooper), but Mancuso gradually devolved into outright megalomania during her stay.
 * The original series of Doctor Who portrayed Nero this way in the serial "The Romans"
 * The new series' Master, who under the alias of Harold Saxon became Prime Minister, despite still being as mad as ever, if not more so.
 * John Simm had actually played Caligula in a made-for-TV miniseries in 2004, with copious amounts of ham (oh yes). Later, Simm has been quoted as saying that Caligula was just a dress rehearsal for the Master, and that he partially based his performance on Caligula.
 * In Blackadder II, Queen Elizabeth is The Caligula Played for Laughs.
 * In the 1998 Merlin series, King Uther became this shortly before his death.
 * Wonder Woman TV series: Marion Mariposa, from episode “Screaming javelins” is wildly irrational, violently moody, very intolerant of being told anything he doesn't want to hear, and totally in control of a micronation, submarines and his mercenaries. He infiltrates the US by sky diving, kidnaps Olympic athletes in an attempt to gain popularity for his own micronation, Mariposalia, and his Arch Enemy is not Wonder Woman, but IADC agent Diana Prince

Professional Wrestling

 * Vince McMahon has been portrayed as the ultimate Caligula in Professional Wrestling. The phrase "Don't Cross The Boss" comes to mind. If you do, you might be forced into a handicap match with the monster heel of the week, have to join Vince McMahon's 'Kiss My Ass' club or simply be told that "YOU'RE FIRED!!!!"
 * Eric Bischoff was WCW's Caligula, was WWE's Caligula when McMahon chose to step out of the spotlight, and is currently TNA's Caligula. Though Your Mileage May Vary on that last one.
 * Triple H during the McMahon-Helmsley era and later during the Evolution era.
 * Recently Vickie Guerrero has been wrestling's number 1 Caligula. Cross her and you can kiss both your dignity and your balls goodbye.
 * EXCUSE ME!!!
 * There is a new Caligula in town; his name is John Laurinaitis.

Tabletop Games

 * More than a few planetary lords in Warhammer 40000 probably fit into this category, but special mention must be made of High Lord Goge Vandire, who in the 36th millennium managed to take control of both the Imperium's Administratum and Ecclesiarchy, beginning the Reign of Blood. Vandire was notoriously paranoid and ordered the deaths of millions and the destruction of entire worlds due to real or imagined plots against him. He eventually developed a phobia of light and took to wandering the darkened corridors of the Imperial Palace while muttering to himself, and was ultimately killed by his all-female cadre of bodyguards to end the devastating civil war. In the four thousand years since then, the Imperium has all but destroyed itself waging penitent crusades to atone.
 * Ravenloft loves this trope. About half the domains are ruled by Caligulas (even if they're not the actual dark lord). Some examples include Othmar Bolshnik, who's on the brink of declaring himself king of a nation that withholds the title of "king" for their mythical religious ruler; Ivan Dilisnya, a paranoid opera fanatic who sends suspected enemies, actors who displease him, and anyone else he has a problem with to his Play Room; and Vlad Drakov, who seems to be the creators' attempt to put Vlad the Impaler and Hitler in a blender and see what comes out.
 * Paranoia is a Tabletop Game based solely on being controlled by a Caligula named "Friend Computer."
 * Lies spread by Commie Mutant Traitors. Friend Computer is flawless and all-knowing, and works tirelessly to ensure the safety and well-being of all citizens of Alpha Complex. Will the citizen who wrote the above entry please report to the nearest Termination Booth. Further, all citizens who read this Commie Mutant Traitor propaganda are declared to be irreversibly contaminated, and are to report for termination at once. Please note, failure to report for termination is grounds for immediate termination. Have a nice day!
 * Vampire: The Requiem loves this trope, and the entire Ventrue clan more or less exemplifies this tendency. While it's possible for other clans to go Caligula, 9 times out of 10 it's a Ventrue. This is because they not only have lordly instincts, but their clan weakness is a tendency to easily pick up Derangements if they fall down the Karma Meter. So if a Ventrue Prince has to make the hard choices, and is able to rationalize them away, the crazy's going to start to leak through sooner or later...
 * The Ventrue have dozens of bloodlines, all based on this concept. Just want to be a crazy? Try the Malkovians. Creepy obsessive shut-ins? Malocusians. Sadistic gluttons? Macellarius. Ventrue supremacists with overhanging racist/nativist tendencies? Deucalion. Crazed worshipers of divine architecture? The Architects of the Monolith. In fact, in a possible creation myth explained in Mythologies, Caligula was, in fact, the first Gangrel. Julius Caesar was the first Ventrue. Bullshit, yes,.
 * Werewolf: The Apocalypse had the Silver Fangs, the "ruling tribe" of werewolves, who, thanks to inbreeding with the royal houses of Europe, had an increasing tendency to be off their rockers.
 * Exalted: Anyone whose soul is affixed to the Exaltation will behave this way due to death-curse from the creator-gods they murdered, but Solar Exalted takes the proverbial cake.

Theater

 * William Shakespeare's Richard III. Starts out a gleeful villain and ends completely insane.

Video games
"Luca: Do you want to live so badly!?!?!? Villager: Y-yes! I'll do anything! Luca: In that case, act like a pig. Villager: Huh? Luca: I said ACT LIKE A PIG!!! Villager: Y-yes! All right! *on four, making pig noises* Luca: Hoo hoo hoo ha ha ha!! This is so fun...
 * For examples where the game allows you to be The Caligula, see Cruel Player Character God.
 * Halo's Covenant Prophets tend to fall in this category, especially the main trio. They know the whole Covenant thing is a load of crap. They just want to genocide humans because the humans are inheritors of the forerunners, and proof that the forerunners were physical beings and thus proof that their religion is all lies. Truth really stands out, by the end he's clearly a complete psychopath.
 * Fun fact: the canon scientific name for the Prophet species is Latin for "Worms of Treachery."
 * Lord Dimwit Flathead, the most well-known (and infamous) ruler of the Great Underground Empire in the Zork series, was particularly known for his excess - a coronation ceremony that took thirteen years to organize and carry out, the 3000-gated Flood Control Dam #3 (which served absolutely no purpose whatsoever), the creation of a subterranean desert mountain in a cave below his castle, and a 98% tax rate (and on the day of his death he proposed to adopt all his subjects and cut off their allowance to raise taxes to 100%) instituted to pay for such grand civic works. His last work was to be the creation of a new continent shaped in his likeness. Fortunately for mapmakers, he died before the project could be started.
 * King Bowser from Super Mario comes off this way in the RPGs. Also King Croacus in Super Paper Mario. The latter is justified in that
 * King K. Rool from Donkey Kong Country. It got so bad that apparently his minions deposed him and replaced him with a robot.
 * Anybody who has ever played Suikoden II for more than five minutes knows that Prince Luca Blight may even dwarf Caligula in the Axe Crazy psycho department. This is a man who had his country's equivalent of the Boy Scouts murdered to restart a pointless war, and when burning entire towns to the ground for the hell of it, would round up, torture, and slaughter every single villager one by one (including women and children) personally while laughing merrily with a smile on his face. Deconstructed when

Villager: So does that mean...

Luca: DIE, PIG!!!!!!! *slashes villager to death*"

"Vath: Dwarves are a hearty breed. That is why I allowed them to live as my slaves. If a few die then we are just pruning the weak branches from the strong tree."
 * Mad King Ashnard, Social Darwinist villain of Fire Emblem: Path of Radiance. In order to be crowned king, he orchestrated a plague that wiped out a large amount of his country's population to get rid of the many nobles who were ahead of him in the line of succession. Notable for attempting to start a worldwide conflict and release a dark god on the world just because he felt like it. After touching an amulet that was established to drive most humans into a mindless killing rage, his personality remained unchanged, the implication being that he couldn't possibly become any worse than he already was. Interestingly enough, he wasn't considered to be a bad ruler by the common people of Daein, largely due to his policy of awarding high-level positions to anyone of sufficient skill.
 * King Zephiel in FE6 is pretty far off the handle, too. After all, the most seriously disturbing facial expression in FE7 is Zephiel's mad gaze at the end of the epilogue...and this is a game whose Big Bad has a Mad Eye with a nasty scar over it. Yeah, he's seriously wacked... and the saddest thing is that he wasn't always like that.
 * Dwarf Fortress: dwarf nobles have a tendency to sentence dwarves to "hammerings" (usually fatal, but not always) when their mandates are not met.
 * A somewhat more humorous example of the trope is referenced in The Elder Scrolls IV: Oblivion's back story, detailed in the in-game book The Madness of Pelagius. Pelagius was given an amulet that drained his sanity over the years. Early on, his weight would shift alarmingly from overweight to anorexic. He was known to have locked foreign princes and princesses in his room with him until their countries threatened to wage war, but his madness became much more noticeable when he stripped naked during a speech. This was before being crowned emperor. When an Argonian diplomat came to Tamriel, Pelagius insisted on speaking in what he believed to be its "natural language:" Grunts and squeaks. The book mentions him ordering his servants to clean the palace early in the morning; he is said to have defecated upon the floor to give them something to do, but this is described as "probably apocryphal." After he began to bite and attack visitors to the palace, he was moved to an asylum, his last act on Earth being to outlaw death. On his deathbed. This is a borderline example, since he didn't actually rule the empire.
 * The Elder Scrolls also has Sheogorath, appropriately the god of madness. He features heavily in Oblivion's Expansion Pack, where the player can visit his realm. Though not nearly as dangerous or unpredictable as other Caligulas, Sheogorath does have his eccentricities, including going into a rant about cheese while briefing his champion on a mission, making burning dogs fall from the sky, alternating randomly between happy and violently threatening, and.
 * He is also implied to have several personalities and random, semi-frequent bouts of more specific neuroses, such as hypochondria. And anyone who grows facial hair is to be executed. Because only the Lord Sheogorath is allowed to grow a beard, obviously.
 * In Skyrim, it's shown that Pelagius' mind is the vacation spot of Sheogorath. When the player stumbles upon it, Sheogorath actually tasks you with curing Pelagius' madness by strengthening his self-confidence, ridding his night terrors and conquering his fear of his mother.
 * In Clive Barker's Jericho (by Clive Barker), the hedonistic Governor Cassus Vicus was banished to the very edges of the Roman Empire by Caligula himself.
 * King Bohan in Heavenly Sword is a particularly Hammy example.
 * Viva Caligula from the Adult Swim web site is built around being a crazy tyrant and killing everyone you meet in creatively horrible ways.
 * In the back story to the Homeworld series of RTS games, the Taiidani Empire fell under the control of a particularly... 'unstable' ruler, who then proceeded to compound the problem by massacring all his rivals and decreeing that all future Emperors would be clones of him. The insane policies 'he' carries out during the course of the game lead to the empire being overthrown after the insanely efficient Hiigaran fleet kills 'him'.
 * Final Fantasy VI: Kefka, of course! He was already stark raving nuts when he was serving as the Emperor's Dragon. But when he got hold of the power of the gods and bumped off the Emperor, he got even worse.
 * Yggdrasil in Tales of Symphonia pretty much qualifies: Because
 * Nearly the entire cast of Blood Storm is composed of megalomaniacal Complete Monsters, all of them fighting to become the High Emperor and thus be true Caligulas. Take your pick: the pyromaniac warlord, the ice-blooded king with a superiority complex, a Hive Mind that tortures people for fun, an Amazon hoping to eliminate the entire male gender, the radioactive mutant that intrudes on the contest, the vengeance-obsessed cyborg smuggler, or the spoiled princess. The only good character enters the contest to get everyone to stop listening to the paranoid nuts and actually start fixing the planet.
 * from Mother 3. He passes himself off as a great hero, despite corrupting the once vibrant world into an industrial wasteland, not to mention using anything and anyone he can get his hands on as his personal playthings. At the end, he reveals his plans to awaken the Dark Dragon and destroy what is left of civilization, all for a quick laugh.
 * Zant from The Legend of Zelda Twilight Princess plays this trope to a T.
 * Vath from Adventure Quest Worlds. He enslaved the dwarves, making them work without food, water, or even weapons. He's a lousy dictator, believing that their weakness and hunger was fine with him and not even caring if they starve to death as long as they forge enough Chaos Gemeralds for him to use to hatch the Rock Roc.

Visual Novels

 * Gilgamesh in Fate/stay night. So damn bad. The prequel reveals that he's so batshit crazy irresponsible that he might as well be a Starfish Alien as far as Saber is concerned. At least with Rider (Alexander the Great), a self admittedly horrible tyrant, she could debate the policy a king should have as at least he thought a king should have one.

Webcomics
"Black Mage: What is this? King Steve: It's no cone! Thief: It's a cube. King Steve: Oh, no. That's a common misconception. It's a stube. Thief: A what? King Steve: The seven-sided cube. I invented it. Black Mage: There are only six sides. King Steve: The seventh side is the inside."
 * King Steve from 8-Bit Theater is a Dead Baby Comedy Cloudcuckoolander. One of the least dangerous things he has done was betting the office of King in a poker game. He lost the game to a piece of string..."whom" he then assassinated by cutting it in two with scissors when no one else was near.
 * Very literally Dead Baby Comedy as that's what his shoes are made of. They tend to rot, however, so he has to get new ones "Fresh daily."
 * One if his frequent "elections" simply gave the population the choice of either King Steve as supreme ruler, or to get a sword in the head. 52% of the survey population died.
 * Another time, he set up a snow cone stand. This might sound mundane at first, but the Light Warriors noticed something strange about the aforementioned snow-cones, leading to this exchange:


 * He also thinks that he invented inventing, started a war to force pacifism on the elves, and was once told he had news and enthusiastically asked "does it involve cupcakes?" and decided he didn't care when the answer was no, thinks he designed his castle to be four hundred years old, and apparently knew what a robot version of himself was saying even after the robot exploded. If he isn't a ditz then nobody is. Did we mention that he is unable to tell the difference between his daughter and his Beleaguered Assistant Left-Hand-Man Gary? (In case you were wondering, his right-hand-man is a coffee stain called Rodney.)
 * Stephen in Terror Island, who somehow managed to be elected Czar of Geography City, largely wields his power to sentence innocent people to indentured labor at Jame's restaurant and to attempt to force Sid to buy groceries. His successor Blueteen isn't much better, sending people to prison (including himself) for attending parades. Not only that, but the parade was actually only supposed to be for stuntmen. Why? Because he had just solved the problem of Jame's stuntman no longer being bound by law to him for jaywalking by telling Jame to just hire him.
 * The Baron in Spiky-Haired Dragon, Worthless Knight is as much of a Caligula as he can be without pissing off higher-level nobles and fellow barons, which is still a lot, especially to the title character (the knight, not the dragon).
 * Chancellor Valorum in Darths and Droids. The annotation explains that they wanted to make him more interesting than in the movie version, who was bland and boring. Consequently, he becomes a maniac who praises the droid army for overthrowing their human oppressors, urges people to replace their bodies with cyborgs, and demands that all shall "Kneel Before Valorum!". His getting voted out of office makes a lot more sense now.
 * Kharla'ggen Vel'Vlozress of Drowtales is extremely insane, and has a hobby of turning living people into living dolls and altogether has the mental capacity of a young child and no real sense of morality. Despite this she does get a few Pet the Dog moments with her adopted sister, Kiel'ndia (who, despite Kharla being the one who turned her mother into a puppet, seems to get that Kharla doesn't really understand and thus doesn't blame her) and it's suggested that if left alone she wouldn't be so bad.
 * Richard from Looking for Group seems to be this with the town he is mayor of. However his citizens don't mind it since.
 * Christian Weston Chandler plays this trope to the hilt as the Mayor of CWCville in Sonichu. He enacts all sorts of bizarre laws that treat smoking as being as heinous as rape and murder, he brutally slaughters anyone who tries to stop him from doing whatever he wants, and his will is enforced by what is essentially a multicolored hedgehog Gestapo who according to Word of God enjoy full immunity from the law. His civic policy decisions are equally as insane-in Sonichu: The Animated Series, he ordered that the CWCville waterworks circulate orange soda pop instead of water, which leads to fires continually breaking out all over the city.
 * Eridan Ampora (aka "caligulasAquarium") from Homestuck is a number of the royal sea-dwelling troll caste. His primary interests revolve around genocide of the land-dwellers and his many failed efforts at romance. He mostly embodies this trope in his blind self-absorption and poor decision making.
 * A better example of this trope, oddly enough, is the Grand Highblood, Gamzee's Ancestor, who brutally terrorizes the other, lower land-dwelling castes through capricious homicide and psychic nightmares in the name of his Monster Clown religion. However, this is characteristic of the Subjugglator caste as a whole and not a one-off thing.
 * Implied in an Oglaf strip where two princes have been forced into arranged marriages by their father... with a pig and a withered corpse. One prince comments that there should be a rule that you should be forced to abdicate the throne when you start doing things like that.
 * Implied in an Oglaf strip where two princes have been forced into arranged marriages by their father... with a pig and a withered corpse. One prince comments that there should be a rule that you should be forced to abdicate the throne when you start doing things like that.

Web Originals

 * The pharaoh comes off this way in Yu-Gi-Oh the Abridged Series.
 * A milder Caligula appears in v2 of Open Blue, Count Marcus Veneto, who even made his horse his war advisor, in a Shout-Out to the Trope Namer. The 'milder' comes from the fact that he's trying to get his act together. It's implied that this change of heart is the result of Men In Black being sent by two allied empires to intimidate him into doing so. Suffice to say, that hasn't stopped him from requesting an Amazon Brigade for his personal guard and naming them the Killer Bunny Assassination Squad.
 * The Nostalgia Critic during Kickassia.
 * Linkara has some Caligula tendencies.
 * King Harkinian in some of the Zelda CDI YouTube Poops, arguably to the point of rivaling canon characters like Zant and Majora in terms of sheer insanity. This is a man who:
 * Went on a drunken roadtrip in his new Toyota Hybrid and trashing said car not 24 hours after getting it.
 * Got high off of Reese's Pieces.
 * Tried to pay an expensive telephone bill by selling Link on eBay.
 * Shares an incestuous relationship with his daughter Zelda.
 * Makes traitors engage in various, degrading acts in order to receive a pardon, only to laugh at them at the end.
 * Freaked out at the possibility of getting killed while aiding Duke Onkled, sending Link to do the job instead.
 * Shot Link in the gut when asked if he (Link) could play his (King) Nintendo Wii.
 * Responded to one of Link's practical jokes using bazookas (that shot out hamburgers), missiles and a Kill Sat.
 * Lost his shit when Gwonam said there was no dinner left, killing and maiming anyone within a 500 yard radius.
 * Went travelling the world in order to convince people to eat his feces.

Western Animation
"Tallest Red: That was the wrong guy, but... I think everyone gets the point."
 * Kuzco from The Emperors New Groove is one example where The Caligula in question is the Main Character, although he's spoiled, feckless and self-absorbed rather than outright insane.
 * The film implies that his being in the trope at the start of the movie was due to Yzma's influence when he was growing up. On that note, Yzma plays the trope completely straight. After throwing him off the throne, she became all the things of a stereotypical Caligula, especially outright madness.
 * Scar in The Lion King.
 * Adventure Time has Xergiok and Lemongrab. Xergiok is a sadistic, cruel, jerkass leader who delights in spanking his subjects and intimidating them. Lemongrab is a bit of a more sympathetic example--he isn't evil, but he certainly is inexperienced (at being a ruler, AND at being alive) and has anger issues, which eventually leads to literally everyone in the candy kingdom being sent to the dungeon.
 * Avatar: The Last Airbender: Already unstable following the Heel Face Turns of  at the Boiling Rock,   falls quickly into paranoia and fits of rage after Ozai , banishing servants and guardsmen from the country in droves and hallucinating about.
 * It doesn't help that
 * The Almighty Tallest of Invader Zim have tendencies as such, being perfectly happy to put their subjects under such events as Probing Day, where they make Invaders do ridiculous things to entertain them or else suffer a pummeling (pushing some buttons that lead to said Invaders getting beat up by their own technology). The entire principle of destroying a planet to build a parking garage or food court.
 * They also tried to kill their best invader just for being short. They order everyone to retreat from battle just because of their snacks being lost, and one time they punished someone by throwing them out of the Massive into space, but got the wrong person by accident, and just shrugged it off.

"Puddinghead: I know how to think outside the box, which also means I can think inside the chimney. Can you think inside the chimney?"
 * Galvatron from Transformers Generation 1. Spending the time between the movie and season three in a lava pit turned him from the Megatron-but-competent of the movie to... uh... the way we all remember him being. He blasted more of his own troops in his rages than Autobots in battle, and at one point, some other Decepticons told his right hand bot Cyclonus that if something didn't change, they were going to deal with both of them. Too bad no Decepticon civil war ever materialized.
 * Straxus from the comics is even worse. His Animated counterpart, however, is played for laughs on a fan-run formspring page.
 * Lucius Heinous VII on Jimmy Two-Shoes, who is primarily concerned with making sure everyone under his reign is Miserable. Special mention goes to one episode where he casually orders the destruction of one of Miseryville's suns because he felt that three was too many.
 * A tame example occurs in the My Little Pony Friendship Is Magic episode "Hearth's Warming Eve". Pinkie Pie's character in the pageant about the foundation of Equestria is Chancellor Puddinghead, leader of the earth pony tribe and clearly a few apples short of a bushel. She was apparently an elected official, but it's a bit of a mystery why anyone would vote for her.


 * A less tame example is Discord, a God of Evil who ruled Equestria as an Evil Overlord long ago in a reign of chaos and suffering. He's what happens when a sadistic Sociopath with Reality Warper abilities is in charge.
 * The SpongeBob SquarePants special "Whatever Happened to SpongeBob?" has an amnesiac SpongeBob finding himself in a city under the tyranny of a greaser gang who outlawed bubbles just because they have the potential to cause harm.

Real Life
"Stalin: Comrades! I want to propose a toast to our patriarch, life and sun, liberator of nations, architect of socialism [he rattled off all the appellations applied to him in those days] ... Josef Vissarionovich Stalin, and I hope this is the first and last speech made to that genius this evening."
 * Cracked.com lists Caligula among other Rulers Who Abused Their Power in Hilariously Insane Ways.
 * As a general rule, it seems the more power a ruler has, the more likely they'll be to become The Caligula. Also consider that, primarily with the examples from ancient and mediaeval times, part (or more rarely, all) of what we know about these people may be deliberate smear by political opponents after the fact, so don't make the mistake of taking every single rumour at face value and listing it here. Use Rule of Cautious Editing Judgment with modern examples. Listed in chronological order of appearance:
 * Accounts of horrific corruption are told of just about every last emperor of each dynasty in China, which makes them suspect since the usurpers obviously want to paint the old guard in as bad a light as possible to justify killing what the common people saw as divine. Some of these accusations even entered the Chinese language as idiomatic expressions. Here are some highlights:
 * The last emperor of Shang devised a punishment in which people had to walk across a bronze column over a blazing hot fire, threw dissidents into pits of live snakes, and once had one of his few honest ministers killed by cutting out his heart. He was egged on in all of this by his equally horrible concubine Da Ji, who had the son of another minister chopped to pieces and fed to his father because he wouldn't flirt with her. This minister, the Duke of the West, eventually rebelled. A very loose adaptation of the tale can be read in Fengshen Yanyi.
 * The First Emperor of China, Qin Shi Huangdi, and most of his worse excesses came about only after many years of self-inflicted, systemic mercury poisoning (long believed to be a key ingredient in alchemy for the Elixir of Life) though he was hardly nice before. The man was an all-powerful leader who was first to rule all of known China with an iron fist. Being a legalist, he imposed laws that meant All Crimes Are Equal, burned books that didn't agree with his philosophy, and on at least one occasion buried some scholars alive for obliquely insulting him. He also used peasant labor for extravagant projects such as building his own tomb, spiffying up the capital city, and building what would become the Great Wall. Then when he died he had his ministers and concubines be buried alive with him.
 * New Testament example: King Herod the Great, ruler of Judea. Known in the Christian tradition for The Massacre of the Innocents, an attempt on the life of the newborn toddler Jesus (although some historians regard that account as a piece of symbolic storytelling). Much of Herod's bad reputation amongst the Jews (and consequently, amongst Christians) can be chalked up to his being all buddy-buddy with the Romans, who installed him as a puppet ruler. His attempts to bring Roman and Hellenistic culture to Jerusalem probably weren't very much appreciated by those who lived there (remember the Books of Machabees), so his evilness was probably played up a bit. Still, he was extremely paranoid about being overthrown -- meaning that he killed so many of his family members that Emperor Tiberius quipped that he would rather be Herod's pig than his son. Robert Graves' I, Claudius points out that, as Herod was Jewish, his pigs were presumably perfectly safe - although Herod was actually an Edomite. Not technically Jewish, and therefore one reason that he was viewed by Jews as an illegitimate builder of the new temple and an illegitimate king overall. Still, he would not have dirtied himself with personal stock in swine while Jewish leaders were looking.
 * General rule among historians of the Roman Empire: those who were Christians (like Lactatius and Eusebius) adored pissing on the Pagan Emperors who persecuted Christianity, describing them as huge Caligulas, especially Diocletian and Galerius. On the other hand, their Pagan counterparts (like Zosimus) did their best to bash Constantine. Then Christian hagiography took the first phenomenon and ran with it. And we're not even including the Senate-affiliated ones.
 * Again, let's start with Caligula. For example, he allegedly once burst out laughing while entertaining two consuls, and when asked why, told them that it had just occurred to him that he could have them both killed. The imperial guards finally snapped and killed not only him, but his entire family (including his two year old daughter) just in case it was In the Blood. The only survivor? His uncle Claudius, who became the next emperor (and managed to survive for quite a while by using Obfuscating Stupidity).
 * However, the reliability of the stories about Caligula is very much questionable. It's certain that he wanted to increase his authority, and this made him unpopular; so after his death, he was accused of pretty much every kind of evil act imaginable. He was probably a bad ruler, but not as evil and crazy as commonly portrayed.
 * Not to mention, it's speculated that he could have been brain damaged after a severe illness. Before that, he was more or less fine; after recovering, he started acting like we know.
 * Emperor Nero, the nephew of Caligula, wasn't exactly a bastion of sanity, either. Keep in mind that this is the guy who loved the theater so much that he actually forced people to watch his performances, and locked them in the auditoriums so they couldn't leave.
 * Nero also brutally persecuted many groups including Christians, and he would have the men, women, and even the children thrown to the lions for his own amusement. He also worshiped himself, believing himself to be the greatest artist that ever lived.
 * Though considering everyone who wrote about the guy (except his friend Senectus, who praised him) personally knew and hated him, kinda makes it hard to tell if anything they said about Nero was true. Though he probably was a great lover of the arts.
 * And Domitian. He would sit alone in a room and stab flies with a pen, among other...eccentricities. Again, if you believe what ancient historians wrote about him. Which, given his relationship with the senatorial class, the most likely audience and source or authors in those days, was unflattering. Not helped by his Conspiracy Theorist fame, at least partially confirmed by his prosecutions of many different groups in the Empire. Christians were just one of the people he ordered to arrest, imprison and execute.
 * Commodus: His reign was so terrible that historians believe he single-handedly ended the Pax Romana. Although he was not so much evil as he was power-mad and blissfully ignorant of his responsibilities as Emperor. He believed himself to be the reincarnation of Hercules and personally fought in gladiatorial games - which were always fixed for him to win, of course. He also successfully devaluated Roman coinage, while simultaneously raising taxes, creating a wave of poverty never seen since the days of the old Republic. There's a reason a toilet is sometimes called a "commode".
 * Again, many of the above are senatorial-made fake-portraits of him, for sure that of the fixed matches in the arena.
 * Then there's Elagabalus, a sex-crazed Transvestite (and possibly Transsexualism) who became emperor at fourteen and was reported to have prostituted himself. He also allegedly held parties where guests were showered in rose petals until they suffocated, and was looking for a surgeon who could create a vagina somewhere on him. Then again, like with Caligula, these may have been rumors blown out of proportion by later historians.
 * Mansa Khalifa of Mali is best remembered for insanely firing arrows at random people from his palace rooftop.
 * Both Charles VI of France and his grandson Henry VI of England were quite mad for some time. It was an episodic thing, but still difficult to deal with. Most famously, Charles believed himself to be made of glass at times, while Henry completely lost the ability to know what was going on. They didn't quite play the trope straight, though, since relatives and powerful noblemen stepped in to take the reins of government. Which led to the whole Wars of the Roses thing in England. And Charles's feeble condition did France no good in the more or less on-going Hundred Years War.
 * Though certainly not the ruler for whom this trope was named, Ivan Vasilyevich -- also known as "Ivan the Terrible" -- epitomizes this trope. Although he started off as a benevolent ruler, a near fatal illness and the death of his wife plunged him into madness. Thousands died from starvation and plague during his reign, and he ordered the massacre of the entire city of Novgorod, nearly 60,000 people. He was eventually assassinated by those who feared they would be next. Not only that, he also accidentally killed his favorite son, after the son tried to protect his wife from his father's abuse. He was also in the habit of marrying women, murdering them, and executing whomever he wished on charges of murder. He had a much dreaded private army, whose members were rewarded with the property of the victims of their atrocities. Interestingly, his bad rap came mostly due to his acknowledgements of his bad deeds. A deeply religious man, he had seen himself as a terrible sinner, so he vexed and vaned about his sins all over the realm as a penance. His enemies took it, and ran with it -- as many sources say, compared to other XVIth century monarchs Ivan the Terrible was much better than most. Although his prayer sessions usually excited his desire to torture people in various horrible ways (including alternating between pouring freezing and pouring boiling water on them until their skin peeled off), meaning he wasn't that much better. These were par for the course for these times, which were pretty rough indeed -- a common execution for counterfeiting money throughout much of the Europe was to pour molten lead down convicts' throats, for example. It certainly was that the overall number of people executed on his orders during his whole reign was just about the number of people killed in the St. Bartholomew Day's Massacre alone. So, while he was certainly pretty much apeshit during his late years, he was hardly worse than, say, Henry VIII - who didn't have anywhere near as many people killed, but has a similar if not worse reputation these days. He (Ivan) eventually died from some unidentified illness. There are a lot of speculations that he was poisoned, but there wasn't any proof (his remains did contain high doses of mercury, but it was a common medicine at the time), he wasn't really young back then (54, actually), and lived a life of excess (mercury was used as a cure for syphilis), so it's more probable that his death was natural.
 * Giles de Rais, a personal confidant of Joan of Arc. Upon his departing her service, he indulged in some of the more extravagant public festivals in France's history to that date, bankrupting his family and feudal territories in the process. Oh yes, he also did unspeakable horrific things to several hundred little boys, none of whom survived the experience. As with a few others on this list, it is considered possible by some modern historians that de Rais' atrocities were played up by his enemies (or even that he was outright framed) so they could get choice pieces of the duchy of Normandy for themselves. He pleaded guilty at his trial probably mostly because that way, while his family and descendents would lose some of their lands, wealth, and prestige, they wouldn't lose it all, which is what would have happened if he'd pled innocent and been found guilty anyways, a very likely outcome in the late Middle Ages.
 * Vladislav Basarab III of Walachia, better known as Dracula, was alleged to have committed many shocking crimes, such as impaling his enemies and forcing women to eat their roasted children. However, the most notorious crimes were attributed to him by his enemies, who had every reason to want his memory slandered. It does sound like he was somewhat unhinged, probably due to an abusive childhood as a hostage to the Turkish sultan, and he had a twisted sense of justice. After a guard caught a thief inside his home, Vlad had the guard killed -- because the thief was a common scoundrel, but the guard should've known better than to storm into his home without permission. In addition, Dracula was doing his level best to keep the Turks from invading his country, and thus had an interest in looking as terrifying as possible. Supposedly, Mehmet the Conqueror, a man known for conquering the Byzantine Empire, turned back after encountering a huge forest of stakes with impaled bodies on Wallachia's border. Note that the main difference between Vlad Tepes and most other Caligulas are that while a regular Caligula would kill you because he felt like it, Vlad would kill you because you commited a crime.
 * It's because of this desire to protect his people from the Turks that Romanian writers and poets to this day consider him a national hero who was "harsh yet fair", and that he kept his country safe from invaders and purged Wallachia of internal corruption from its nobility class.
 * It would be easier to list the monarchs of Spain who weren't insane (between the early 16th Century and the elimination of the monarchy in the 1930s). That's what you get when you mix Hapsburg and Bourbon blood and start in-breeding it to ridiculous levels (there were at least two occasions when a king of Spain married his own niece and had children by her). You want a good reason why Spain ceased to be a world power? This is it.
 * Sweden's own Caligula was Erik XIV. He earned the nobility's resentment by marrying a common girl for love, and thereafter descended into a spiral of increasing paranoia and delusion, culminating in the slaughter of the influential Sture family, after which Erik panicked completely. He was deposed and imprisoned by one of his brothers who, supposedly, later had him killed with a bowl of poisoned pea soup. Much of his ill-advised actions toward the nobility was later blamed on his Evil Chancellor, Jöran Persson And boy does he look evil.
 * Elizabeth Báthory, a Hungarian noblewoman whose activities earned her the title "Countess Dracula," reportedly murdered hundreds of young peasant women. While fanciful accounts pin the reasons for her doing so on her wanting to bathe in their blood and remain young, the truth may be that she just did it out of sheer cruelty. Thus, she earns a place as one of the rare female Caligulas. Unlike most people on this list though she was not in a direct position of power, she was the wife and later mother of a minor count, however through her linage and relatives she was able to escape prosecution for several years, until the peasants she preyed on got wise to her and she moved on to the daughters of other nobility. Strangely recently some people have been attempting to give her a Historical Hero Upgrade claiming that she was attacked because she was a woman in power and they wanted her land and money despite the fact she technically did not have any power or land.
 * Alexandru Lăpușneanu, prince of Moldavia, was overthrown at one point. He then returned several years later, intending to exact revenge on the noblemen who betrayed him. He did so by inviting them all to dinner, killing all 49 of them, and making a pyramid out of their severed heads. He's present in the old chronicles of Moldavia, but the main source Romanians have for his life is the highly-fictionalised and exaggerated account from the novel with the same name by Costache Negruzzi, so it's really hard to tell which bits were true and which were just exaggerated by Negruzzi. And in the novel, he does that in order to "rid" his wife of her "fears" (read: terrify her into not objecting to his authoritarian rule any further).
 * Zhang Xianzhong played this trope with frightening efficiency. After conquering China's Sichuan region, he ordered the execution of anyone who opposed his rule - which happened to include everyone, regardless of whether they were genuinely on his side or not. The man was literally more concerned with watching people die than tending to his country, even going so far as to demand his own soldiers to kill each other and setting up a literal "monument to nonexistence" as the Manchu Dynasty was closing in on him. By the time he was killed, over 99% of the population of Sichuan was wiped off the map.
 * The flamboyantly mad Sultans of the Ottoman Empire, particularly in the 17th century, fit this very well. Coincidentally, the Ottomans' old enemy Spain was having similar problems with her monarchs at around the same time. This was owed not to royal inbreeding but partly due to the atrocious conditions in which Ottoman princes were raised.
 * Christian VII of Denmark, who was about as close as you could get to Caligula in the 18th Century. He started showing signs of insanity when he was ten, turned out to be schizophrenic and had very little self control. He was an alcoholic before he hit puberty, regarded a fun time as going through the streets of Copenhagen with his buddies beating up passers-by, then retiring to a nearby brothel for a nice, quiet orgy. It was said that the only person he wouldn't have sex with was his wife (although they did manage to have a son). He did manage to find a doctor who could help him, a German named Johann Struensee, and unlike most on this list actually understood something was wrong and tried to fix it. He ended up making Struensee Prime Minister, after his wife started sleeping with Struensee (something Christian didn't mind because that meant that he could sleep with whoever he wanted to, although he did end up claiming the couple's daughter as his). He ended up falling under the influence of his Wicked Stepmother, who had Struensee executed and the queen exiled. He spent the rest of his life certifiably insane and like a male Ophelia and was only trotted out in public for ceremonial occasions and purposely left out of government, despite the fact that Denmark was still an absolute monarchy at the time.
 * Crown Prince Sado of Korea, the crown heir of Korea was going to be this. He regularly burned sets of silk clothes, raped servants, and killed them. Eventually, he was executed by being shut inside a chest for eight days.
 * However, as that link states, he may have been framed and deposed of as a rival, with stories of his cruelty being exaggerated (or even made up) so that they would feel more "justified" by executing him.
 * Shaka Zulu. You know you're crazy when you have hundreds of wives and kill any child they give birth to.
 * Joseph Stalin, brutal sociopath and paranoiac who amassed more power than any of the Tsars who had ruled Russia before him and used it to cause the deaths of 20-odd million Soviet citizens (conservative estimate) and generally set the bar for twentieth century tyrants, and whose sheer death toll alone would put him on this list even if nothing else would. A massive cult of personality developed around him as a Godlike figure of benevolence and superhuman strength, he accepted titles such as "Coryphaeus of Science," "Father of Nations," "Brilliant Genius of Humanity," "Great Architect of Communism," "Gardener of Human Happiness" and more, simultaneously saying to his underlings that he desired to be remembered for "the extraordinary modesty characteristic of truly great people". At the same time, however, he appears to have been more than a bit cynical about it, suggesting that he didn't really buy into his own cult but just used it as a tool to maintain power; he was even known to joke about it:

"Stalin is addressing a crowd when, during a pause in his speech, someone sneezes. He yells out, "who sneezed?" No one will admit to it. "First row, stand," Stalin orders. They do. "Shoot them." The first row of the crowd is led out by the guards and executed. "Who sneezed?" Stalin asks again. Still nobody says anything. "Second row, stand." They stand. "Shoot them." The second row of people is led out and executed. "Who sneezed?" Now one man comes forward, grovelling, and, in the most miserable voice imaginable, confesses: "it was I who sneezed, Great Comrade Stalin." There is silence. Stalin leans forward. "Bless you, comrade." - - - One day, Stalin arrives at his office ready to work (probably mid-afternoon, and maybe still hung-over). He checks the drawers for his favourite pen, but can't find it. He calls Beria in. Stalin: Comrade Beria, someone has stolen my pen! I will not stand for this! Find them and punish them! Beria leaves, and Stalin finds another pen and gets to work signing death warrants or some such. Much later, as he is preparing to leave, he finds his pen on the shelf behind him. A little embarrassed, he calls Beria back in and asks him how the investigation is going. Beria: Good news, comrade Stalin! Three men have confessed to stealing your pen, and they have all been executed. All of them acted independently!"
 * Of course, anyone who didn't laugh probably found themselves getting a bullet in the back of the head before too long, so that's not exactly definitive evidence. There is also the story about how he disciplined his son Vasily Stalin. After Vasily's school teachers complained that he was an arrogant and disobedient prankster, Stalin, while taking off his belt to give his son a whipping, told him "So you think you're Stalin, eh? Well, you're not Stalin! Even I am not Stalin! Stalin's way up there [points to the sky]!". Let's end with some old Soviet jokes about Stalin...


 * Stalin's "cult of personality" was relentlessly parodied in The Onion on an article for when he died. "Soviets mourn loss of beloved Stalin: who will crush our spirits and destroy our will to live now?"
 * Compared to some of those he shares this list with, Adolf Hitler was almost mundane; he was known to shun and disdain the more grandiose affectations that many tyrants took upon themselves. Yet he belongs here too; even if not initially (and there are certain persistent rumours about his private life and sexual predilections that make this questionable), then certainly by 1945. Even leaving aside the fact that the Holocaust alone could never have been ordered by an entirely sane man, by the end of the war he so self-identified with Germany and the German people that one of his final orders before his death demanded the complete annihilation of Germany's entire industrial, agrarian and urban capabilities, because he genuinely believed that Germany could not survive his passing and that the German people deserved to be punished for failing to meet his standards. Fortunately for Germany, saner heads prevailed and the orders were ignored. Unfortunately for Germany, it was half occupied by the Soviets...see above.
 * Khorloogiin Choibalsan, Communist leader of Mongolia, is also considered as this. A follower of Stalin with a pan-Mongolian vision, while there were infraestructure improvements and literacy rates improved under his rule, he would conduct many Stalinist-style purges in the country, killing thousands of potential enemies (specially Buddhist lamas and local nobility). He also re-named more than one place in Mongolia after himself - like the Bogd Khan Uul mountain, and both the province and the city of Choibalsan.
 * Indonesia had the peculiar fortune of being led by two of these back to back during its first five decades of independence.
 * The first, Sukarno, more than provided the eccentricity of the Caligula: While he was charismatic and, by all accounts, tremendously brave, he was also vain, autocratic, and calamitously inept at affairs of governance, ushering in triple-digit inflation and nearly leading the nation into famine (while erecting monuments to himself all over Jakarta and starting a war with Malaysia) by the time he was deposed...
 * ... by Suharto, who supplied the Caligula's brutality. Originally a mid-level army officer, he used the instability of Sukarno's last years to consolidate more and more power, culminating in a nation-wide anti-communist purge in 1965 that killed at least half a million people. It's true that, after he finally took the last of Sukarno's powers, he helped pull the economy out of its rut, but he only used this new prosperity as a chance to rob the nation to the tune of $30 billion or so.
 * Mao Zedong, while he was a born revolutionary and a calculating politician, he was an administrative moron, particularly when it came to economics. His enthusiasm for Peasant Revolution! won out over his reservations about the wisdom of politicising all of Chinese society inclusive of the civil service, which became an integral part of the Communist Party... which resulted in a civil service which would be punished if it failed to implement all the Party's directives to the letter and was rewarded for telling the Party's leadership what wanted to hear. This backfired spectacularly under the second 'five-year plan' of economic development - a.k.a. 'the Great Leap Forward' - which mandated infeasibly large increases in agricultural and industrial output. This directly resulted in agricultural shortfalls and then famines which went unacknowledged and unaddressed by the Party for many months, if not years. Then there was the cultural revolution, which saw the removal of all students from colleges and universities to work on farms - that they might 'learn peasant values' - and/or carry out the Cultural Policing work of the 'Red Guards'. The resultant loss of cultural heritage and the effects of the collective psychological trauma are incalculable, but in a few words they were really, really bad and nobody who lived through them likes to think about those times. When Mao finally died, the blame for the excesses of the revolution was shunted onto the 'Evil Chancellors' of the 'Gang of Four'. By attributing the madness of the revolution to a conspiracy at the highest levels of government, they completely avoided addressing the extremely uncomfortable issue of the widespread popular involvement in the revolution - which in some cases saw Red Guard cadres put down by armed force when they refused to stand down and denounced the Peoples' Liberation Army for not being revolutionary enough.
 * When Pol Pot rose to power, he personally wanted to change Cambodia as he saw fit. He banned and abolished everything he considered as bourgeoisie (money, religion, sports) and also declared Year Zero, which would be the Khemer Rouge's new calendar. His first step as ruler of Cambodia was to force everyone out of the cities to work as slaves in the fields; then, he ordered the execution of people he branded as enemies... namely those who were religious, intellectual, sickly, and those who wore glasses. His goal was to turn Cambodia into a Communist paradise, and spent most of his time hunting down perceived enemies rather than running the country. He also wanted Cambodia to be completely self-sufficient, which though not crazy as such - most nations try to produce as much as they reasonably can domestically - was and is completely impractical given the country's very limited resources and industrial base and his fervent opposition to any sort of advanced education. If that wasn't enough, he declared himself as Brother Number 1, and had all children refer to their real parents as uncle/aunt.
 * Uganda's Idi Amin Dada, whose megalomania extended to bestowing upon himself such titles as "master of all the beasts of the earth and fishes of the sea". The full title he preferred was, according to The Other Wiki, "His Excellency, President for Life, Field Marshal Al Hadji Doctor Idi Amin Dada, VC, DSO, MC, Lord of All the Beasts of the Earth and Fishes of the Seas and Conqueror of the British Empire in Africa in General and Uganda in Particular". The man was totally crazypants, but he knew how to come up with a good title. Another of his self-bestowed titles was "The Last King of Scotland". Yes, Scotland. As part of his "heroic black leader" shtick, he also had all white residents of Uganda carry him through the streets of the capital on a gilded throne, and then kneel before him and recite an oath of loyalty and after his bizarre alliance with Israel soured, he planned to erect a statue of Hitler in Kampala. See The Last King of Scotland for a fictional depiction.
 * Jean-Bédel Bokassa, self-proclaimed Emperor of the Central African Empire during the late 1970s. He adored Napoleon and tried to fashion himself after him as much as possible. His coronation ceremony cost a third of the country's entire budget for the year, and to this day rumors linger that at the ceremony, he served human flesh as the main course. He killed 100 schoolchildren at once after they didn't wear the government-mandated, expensive school uniforms. Embarrassed and outraged, France ended up overthrowing him.
 * Romanian dictator Nicolae Ceaușescu. Just check out the modest palace he ordered built for himself in the center of the capital, at the same time that he was exporting everything that could be exported to pay off the national debt and leaving Romanians to suffer long queues for empty stores, shortages and power cuts. For good measure, he banned abortion and contraception to forcefully increase the country's population at the same time as he led it into an economic disaster, creating the now-infamous trope of Romanian orphanages. And let's not forget his creepily and completely erratic behavior during the Romanian Revolution, the only violent Hole in Flag revolution. Crazy to think that he was liked by the West when he first came into office for openly defying the Soviet Union.
 * Turkemistan's Saparmurat Niyazov was a thorough nut. His antics included building a solid gold statue of himself designed to rotate to always face the sun, changing the Turkmen word for "bread" to "Gurbansoltan" (his mother's name), naming January after himself and September after a book he had written, instructing all citizens to chew bones to strengthen their teeth, and in a crowning moment of lunacy, decreeing that an ice palace large enough for 1,000 people be built outside the capital. The capital is in a desert.. He even instituted a new compulsory state religion based on that book he wrote. Which happens to be an autobiography. L. Ron Hubbard, eat your heart out.
 * Saddam Hussein was a megalomaniac. Uday, his son, was worse. House Of Saddam, a 2008 Miniseries, actually had to tone him down. Among other things, Uday had oversight over Iraq's Olympic Games commitee. As part of his self-appointed duties in that office, he had Iraqi athletes tortured if they peformed too poorly. Saddam's other son Qusay was maybe a bit more sanish than Uday, but he was infamous for killing political prisoners to make room for more prisoners.
 * Robert Mugabe of Zimbabwe seems to verge on this every so often - although he may be toning down a bit in his old age and with being forced to work with the parliament these days. Still, single-handedly turning Zimbabwe from Africa's "bread basket" to a starving, destitute nation. May well go as evidence that good revolutionaries don't necessarily make good politicians.
 * "Dear Leader" Kim Jong Il of the Democratic People's Republic of Korea AKA North Korea. His father, Kim Il-Sung, was known as "Great Leader", and started the whole personality cult thing in N. Korea. He is remembered today as the "Eternal President" of North Korea, outranking his son even in death. No less crazy, certainly (but then, he did start the Korean War).
 * Libyan leader Muammar al-Gaddafi was politically considered more tolerable to many western countries after he stopped overtly exporting terrorism (at least to them). Without having the label "terrorist" attached to him, people started paying attention to things such as his Amazon Brigade of young, attractive bodyguards, his rambling speech at the UN, and his other peculiarities and started coming to the realization that even if he wasn't Terrorist Evil, he's still completely off his gourd. The events of February-October 2011 and his reaction to protestors (having the air force bomb hospitals) have firmly moved him into Caligula territory, and he kept insisting that the Libyans adored him even when almost the whole country had turned against him (which reminds of the aforementioned Ceaușescu).
 * Mobutu Sese Seko Nkuku Ngbendu wa Za Banga. Just to give you an idea of how big an ego the guy had, his name translates to "The all-powerful warrior who, because of his endurance and inflexible will to win, will go from conquest to conquest, leaving fire in his wake." His reign was marked by human rights abuses, inflation, public executions, theft, nationalist culture policing, and the building of a personal airport for shopping trips. Resistance to his rule touched off the Congo Wars, which have left over 5 million people dead.