Regent for Life

The old ruler is dead, but their heir is still a child so a regent is appointed to rule the land instead. This is a plum position, with all the perks of royalty, but it comes with a built in retirement date. When the heir comes of age, the regent must become merely a respected adviser, or retire to his considerable lands. But where's the fun in that? He's been running EVERYTHING, and he doesn't want to give it up!

Usually, the late ruler appointed either a close relative, or a senior churchman, hoping their family ties or religious obligations would stop them from intriguing against the true heir, but this seldom works. Sometimes, there is a regency council instead, but that just adds vicious internal politics to the mix.

When the heir is of age, the story can go several different ways. Perhaps the regent becomes the Evil Chancellor and runs the kingdom through deception, manipulation, or some sort of evil control over the ruler. If he's in line for the throne himself, he may become the Evil Prince. Other times he'll arrange for the true heir to be kidnapped, killed, imprisoned, or discredited. If the heir is of the opposite gender, the regent might attempt to marry them. While such intergenerational political marriages were once common, the Regent's anticipation of the consummation often pushes him over the Moral Event Horizon. If the regent is already married, or forbidden to marry, he may settle for the heir marrying into his family. Subtler regents may try to introduce him to drink, drugs, and other pleasures in hopes that he will find decadence more pleasing than ruling; a grown figurehead is no different from a minor.

Sometimes the Regent is revealed as having been evil from the start, perhaps even having had a part in killing the old ruler. Sometimes, though, they became corrupted by power instead.

And once in a blue moon, the Regent is only called a Regent because the actual King has been gone for a very long time, and the people are (at least theoretically) awaiting his return. Since nobody wishes to disrespect the title of King, the actual ruler of the country is officially merely a regent, but in practice has all the power of a king and isn't usually particularly worried about having to give up power to anyone but his son (or perhaps the next person smart enough to overthrow him).

There is also, of course, the possibility that the heir is an absolute nightmare, and the regent being (and using any method towards staying) in power is the only thing keeping the kingdom free from a tyrant. Expect Black and Gray Morality, Selfish Good, Selfish Evil and other tropes of this nature to kick in as people question the regent's legitimacy (which, admittedly, he lacks) and motives (which may well extend beyond altruistic intentions, especially if his struggles have made him cynical). This can ultimately lead to a horrible situation where both heir and regent are monsters, forcing a third party to step in.

A Queen Mother acting as regent is more likely to act as My Beloved Smother.

Contrast Cincinnatus.

Anime

 * Prozen in Zoids Chaotic Century is a classic example, complete with trying to kill off the kid heir and prolonging a senseless war.

Film -- Live Action

 * The Iron Man movie reveals the Big Bad early on by showing Obadiah Stane to be an example of this.
 * The Ella Enchanted movie, where Sir Edgar orders Ella to kill his nephew so that he can be king.
 * Cardinal Richelieu has elements of this in The Three Musketeers 1993. (Not so in the book, where he is an Evil Chancellor but Louis XIII is already grown up.)
 * Batman Begins has a minor example, as the CEO takes over Wayne Enterprises soon after Bruce loses his parents. Near the end of the film, Bruce simply decides to discreetly buy stock until he was the majority shareholder.
 * Prince Caspian -- the central plot in the movie, as well as the book.
 * The Richie Rich movie features this when Richie's parents go missing (presumed dead). Cadbury is named the benevolent regent of the Rich estate...until the scheming van Dough frames Cadbury for their murder and takes the regent role by force.

Literature

 * Averted with prejudice and in a very Genre Savvy manner by Ezar Vorbarra in Lois McMaster Bujold's Barrayar series. Ezar picked the one man that he knew didn't want Imperial Power to be Regent for his grandson, Prince Gregor. When Gregor finally came of age, Aral willing stepped aside from Imperial power, becoming his Prime Minister in a strictly advisory role. Aral knew that he had succeeded in raising a true Emperor on the day that Gregor went against his advice when dealing with an interstellar crisis (though Aral still found it to be something of a shock.)
 * But Vidal Vordarian from the same series is this on steroids, usurping the Vorkosigan regency by force, then declaring his betrothal to the dowager empress, and himself emperor, all in a few weeks. Oh, and before organizing his coup it's implied he was something of an Evil Chancellor, currying favor with the dowager empress.
 * Miraz in Prince Caspian started out as "Lord Protector" or some other title and slowly took on the title of king by disposing of anyone at Court opposed to him. He raised the true heir, his brother's son Caspian, as his own heir... until he had a son of his own, prompting Caspian to flee the proceeding murder plot.
 * Queen Clothilde in Mercedes Lackey's reworking of Swan Lake (The Black Swan) intends to 'dispose of' her son Siegfried after he marries and conceives an heir.
 * The Stewards of Gondor in Lord of the Rings were a family of hereditary regents. Good ones, though. Unfortunately, the only one we actually meet in the books and films alike is Denethor, mentally unhinged by the loss of his favourite son, the hordes of Mordor at his doorstep, and finally by . In the movies, possibly due to Flanderization, he and Boromir both make it very clear that "Gondor has no king. Gondor needs no king." The book, at least, implies that he was still loyal enough that he would return the throne to the rightful king, should one ever arrive.
 * And in the book, Denethor would have a solid precedent for refusing to give Aragorn the throne: Aragorn's ancestor Arvedui tried to claim the throne of Gondor, and they turned him down.
 * Cersei Lannister in A Song of Ice and Fire becomes regent for her adolescent son, and is heading this way. (Smug Snake that she is, ambition is not her only motivation.)
 * Although bad as Cersei is, she would still be a massive improvement over Joffrey ruling the kingdom on his own behalf.
 * In one of the Deryni series, the regents tamper with the King's Will to increase their power, keep his first son permanently drugged until he dies, kill the second son when they discover he's plotting against them, and plan to kill the third son as soon as he provides a heir, threatening to have his wife raped if he doesn't cooperate.
 * Averted in the Mallorean. The King of Drasnia dies, leaving his young son on the throne. The boy's mother becomes regent and is very careful about steadily increasing his responsibilities, so that he'll be ready once she steps down. (It helps that Belgarion, for all intents and purposes The Messiah, is practically the kid's godfather - everyone would want to take over Drasnia with just a boy-king and a woman running it, but nobody will screw with the Godslayer.)
 * Played straight in the Belgariad with the Warders of Riva, who have been waiting for their king for several hundred years. Like the Stewards of Gondor, they are hereditary regents, though unlike Denethor, the last one welcomes back his king.
 * Alia in Children of Dune. Installed as regent for her brother Paul's twin children, she becomes possessed by the Genetic Memory of Baron Harkonnen and plots to have them killed and consolidate the power of the Empire for herself. Unfortunately for her, she is viciously Out-Gambitted by.
 * In Brent Weeks Night Angel trilogy, the land of Ceura (Basically a fantasy psuedo-japan) is ruled by a regent who is meant to give up his power when a leader emerges bearing the mystical sword of legend. When Lantano Garuwashi (a hero and famed war commander) finds it, the regent plans brings an army to him on the pretext of "testing" the sword's authenticity, actually intending to kill Lantano regardless. Finding this out, the Regent's 14 year old son challenges his father to a duel and slays him, then goes and takes the army to fight for Lantano, their new king.
 * Played with in The Warlord Chronicles. Arthur is appointed regent while his nephew, Mordred, is a child, to return the throne when Mordred comes of age. Arthur completely intends to do exactly that, even though everyone around him insists that Mordred is a Complete Monster and will be a terrible ruler. Arther.
 * The Mistmantle Chronicles had King Silverbirch of an island neighboring Mistmantle become regent until his daughter Larch could take the throne. Eventually he went crazy over a mad lust for silver and tried to have her killed, so Larch is in hiding, waiting for her chance to take the throne back.
 * Prince Thanel tries to set this up in Exile's Valor when he discovers that marrying the Queen isn't enough to make him King. It doesn't work.
 * Dion Morgan, Regent of Nuin "for Our Very Present Emergency" in Edgar Pangborn's DAVY. It is noted by one of the narrators that the "emergency" started as the accession of an insane hereditary President, but came to mean something like "period lasting from the year Your Excellency got away with it until Your Excellency can decently be kicked out" -- which duly happens.
 * In Marion Zimmer Bradley's STORMQUEEN, when Allart becomes king at the end, he appoints the passed over emmasca heir Felix Hastur as his chief counselor, as Felix is likely to live two or three normal generations, and "perhaps between us we can make something like a king." It seems likely that this grew into the pattern depicted in the novels of post-Recontact Darkover, where we find an Elhalyn king left to "keep the throne warm with his royal backside, which is the most useful part of him", while the current Hastur of Hastur customarily wields all the power.
 * A slightly different version is found in Tappan Wright's ISLANDIA, where the King of Islandia is technically regent for Alwin XVII, who was never seen again after a battle centuries before, but who has never been declared dead. Islandia's version of constitutional monarchy came about by this historical accident.

Live Action TV

 * Prince Joffrey in Game of Thrones, as detailed above under Literature.
 * Jack's rivalry with Kaylie in Thirty Rock has overtones of this. Kabletown is a family-run company, her grandfather is the currrent CEO and Jack wants to steer her towards following her parents into "Trust Fund Kid Syndrome" so he can take over the company.

Myths & Legends

 * In the Robin Hood legend, King Richard's brother Prince John acts as his regent during the crusades. While gone, Prince John plots and manoeuvres to retain his despotic rule. (Note that as part of the Robin Hood legends, this is Newer Than They Think; Prince John had no part of the legends until Elizabethan times, when he was introduced into the legend by Anthony Munday's play, The Downfall of Robert, Earl of Huntingdon (1599).)

Video Games

 * Jagged Alliance 2 has it's intro sequence show billboards near Omerta with the caption 'Queen Deidranna- your Queen for life!'
 * This was the plan of both Duke Larg and Lord Goltanna in Final Fantasy Tactics: kill their enemy's preferred candidate as heir (Orinas in Larg's case, Ovelia in Goltanna's case), rush their respective heir in the position of Queen/King, then rule Ivalice as regent.
 * In Dragon Age II, Knight-Commander Meredith takes control of Kirkwall after . She soon begins using her power to crack down harder on mages, causing further tension between mages and templars. She refuses to consider appointing a proper successor.

Western Animation

 * Yzma in The Emperors New Groove, although her official title is Advisor. (And in this case, "for life" really carries some weight..)
 * Avatar: The Last Airbender: It's All There in the Manual that Long Feng came into power when the current Earth King was coronated at the age of four. Though an adult by the time of the series, the Earth King seems happy letting Long Feng rule over most practical matters, and Long Feng, for his part, is such a Magnificent Bastard that he's managed to keep the King from even knowing that the Earth Kingdom has been at war for the last century.

Real-Life

 * It was once thought that Hatshepsut fit this trope. Until very recently most historians believed that she had maliciously kept the throne from her stepson Thutmose III for thirty years, only allowing him to control the Army while she ran everything else. When she died, the story went, Thutmose immediately destroyed or covered up all of her monuments in an attempt to erase his wicked stepmother from the historical record. Recently, however, it's been discovered that Thutmose didn't destroy any of her monuments until decades after her death, and other historians have pointed out that if Thutmose hadn't liked Hatshepsut being in power he could have disposed of her the day he reached adulthood, since he controlled the Army. It's now suspected that Thutmose and Hatshepsut were friends and allies who ruled together peacefully, Thutmose conducting Egypt's many military campaigns while Hatshepsut stayed at home and dealt with the domestic matters that Thutmose didn't care about. As for her name being defaced off her monuments, many historians believe that Thutmose's successor Amenhotep II simply wanted to take credit for building them himself.
 * Another subversion was Ay, the successor to Tutankhamen, who was thought to have killed Tut and stolen his throne. Turns out that Tutankhamen was the last male member of his family and so physically unwell that it's surprising he lived long enough to die from a bone infection at age 19. It's now thought that Ay had nothing to do with his death.
 * Louis XIII of France's regent was his mother, who held onto her power for several years after after he came of age.
 * Richard III was the regent for his nephew, the infant Edward V, but eventually declared Edward a bastard and himself King.
 * Allegedly after killing his nephew.
 * The only ruling queen of the Kingdom of Judah, Athaliah, was regent for her son Ahaziah. She operated as more of a co-ruler with her son and orchestrated the murder of a number of other claimants to the throne.
 * When Edward VI died, his regents tried to put Lady Jane Grey on the throne so they could retain power.
 * The Shoguns of Old Japan were like this trope. The legitimate ruler of everything was officially the Emperor, and the Shogun was more likely than not just a warlord who happened to have the biggest military force around. Officially, the Emperor is under his "Protection" and any act by the Shogun is the Will of the Emperor. Emperors tended to agree. The ones that lived anyway.
 * This is effectively how the Fujiwara clan controlled Japan. The family provided regents for the Emperor in his minority, continued to serve as powerful advisors through his reign, then often "persuaded" him to abdicate in favor of a young heir so they could act as regents again.
 * It become something of of a precedent in Japan. When the samurai rebelled against the court and reduced the entire court, emperor as well as the Fujiwara regent, into their figurehead, the shogunal Kamakura government itself was taken over by regents just 7 years after Minamoto Yoritomo had taken the title of shogun. The next 134 years, all shoguns were themselves figureheads, as was the whole imperial court still including the regent for the Emperor...
 * Let's not forget that the Fujiwara also controlled the Emperor because he was himself mostly Fujiwara: the Fujiwara had defeated the Soga clan for the right to marry the Emperor, and after a few generations, the Fujiwara had completely hijacked the Imperial genome (except for the Y chromosome).
 * It was widely believed that Toyotomi Hideyoshi planned that, should be conquered China, he's going to transplant the entire Japanese political system to China-- the emperor would move to Beijing, Toyotomi's cousin would continue to be his Regent for Life, while Hideyoshi himself would continue to be Just the First Citizen ("Regent for Life emeritus"). The problem is, Chinese sees Regent for Life as something not as peaceful an institution... see below.
 * Kampaku, one of the three titles used for Regents for Life in Japan, is in fact a historical Memetic Mutation of sorts--it comes from the example of Huo Guang in China, below, and literally means the phrase "to present" in that example's context.
 * And after World War One, Miklos Horthy declared himself regent of the Hungarian kingdom. Although the old Habsburg family is still around, the country never got a king again.
 * In fact, Karl I (the last Austro-Hungarian emperor) had never officially abdicated and travelled twice to Hungary to try to reclaim the throne, only for Horthy's forces to stop him.
 * One of the reasons why he turned down being king himself, against the wishes of supporters for a Horthy dynasty, was that he thought himself unworthy for the throne.
 * As George III of Britain became increasingly unhinged, his son, the future George IV, became his regent, and got his own era of British history named after him.
 * Ci-xi. For two consecutive emperors, maybe three. Even to the point of murdering her own son.
 * It's also speculated that she killed the wife (who happened to be pregnant), as well as her sister empress.
 * She held onto the throne until she died, and her three-year-old nephew Puyi became the last emperor of China.
 * Lu Zhi, wife of Liu Bang of Han, is another Chinese example. She presided as the power behind the throne for three emperors up until her death.
 * Tang Dynasty Empress Wu Zetian was probably a semi-example. She ruled as regent for two of her sons, and seized power at the age of 66 to become the only woman to rule as Huangdi in her own right.
 * Huo Guang of Western Han is a rare benign example, being the most powerful person in China between 87 B.C. to 68 B.C. He served as regent for three emperors, deposed the second of the three, and the third was Genre Savvy enough to ask others to present matters to Huo before him--yet he has no intention to usurp the throne and his deposition of an emperor is commonly seen a way to deal with an heir that is an absolute nightmare.
 * There're actually too many examples in the Chinese history to quote here--while most dynastic changes in China between the third to the tenth centuries were the direct consequence of a military coup, the leader of the coup would not immediately usurp the throne. They would, however, sit as a Regent for Life for a period of time before "persuading" the emperor to abdicate in their favour.
 * Catherine de Medici of France acted as Regent while her two underage sons were King and heavily interfered in the reign of her third son, Henry III. It is doubtful they would have retained power without her. She is widely detested for her supposed role in the St Bartholomew's Day Massacre, where thousands of French Protestants were killed. Modern historians suspect that Catherine didn't actually have anything to do the massacre, but given her track record it's not surprising that she was blamed.
 * Queen Victoria believed that she had only by the grace of God avoided a Regent for Life. When she was seventeen and recovering from typhoid fever, her mother's "friend" Sir John Conroy tried to make her sign a document stating that he and her mother would rule in her place even after she turned eighteen. Victoria had the presence of mind to refuse to sign the document, but it was only her accession as Queen at eighteen that stopped Conroy from repeatedly pressing her to make him her regent.
 * Not quite; the hypothetical regent would have been Victoria's mother, not Conroy himself (among other things, there is no way an Irish commoner would have been accepted as regent, a role never given out to people who weren't members of the Royal Family). Conroy would have been the power-behind-the-regent in such an arrangement, and believed that he would enjoy considerable influence with Victoria even after she took the throne, but it turned out she wasn't as fond of him as he thought. And even if she had signed the document, it wouldn't have mattered. Parliament would never have consented to such an arrangement
 * Birger Jarl of Sweden (1210-1266), first The Man Behind the Man of his brother-in-law King Eric "the Lisp and Lame" and managed to get his underaged son Valdemar to be declared King after his death and made himself his regent. Then he beat down a rebellion from several nobles who concidered that cheating.
 * Fun fact: Valdemar was in his late 20's when his father died. One can just imagine the tension in the Royal Court between the now adult King and his father who had been the de facto ruler for decades.
 * Adelaide, Marchioness of Susa and Countess-Corsort of Savoy, outlived all her sons and was the effective ruler of Savoy until halfway through her grandson Humbert II's rule.
 * Johann Friedrich Struensee was royal physician to the schizophrenic King Christian VII of Denmark and a minister in the Danish government. He rose in power to a position of de facto regent of the country, where he tried to carry out widespread reforms. His affair with Queen Caroline Matilda caused scandal, especially after the birth of a daughter, Princess Louise Augusta, and was the catalyst for the intrigues and power play that caused his downfall and a dramatic death.
 * Francisco Franco was officially Regent of the Kingom, amongst other jobs. Despite popular belief he was not a Fascist but an Ultra-Conservative and a Monarchist (the Fascist party came to despise him for this), and was ostensibly holding power until the rightful King stepped in... though he did'nt actually say who that was until 6 years before his death. The man in question was the son of the Legitimist pretender Juan Carlos, who upon Franco's death promptly declared a liberal democracy and constitutional monarchy.
 * Prime Minister Rainilaiarivony of Madagascar is generally thought to have been the man behind the woman for Queens Rasoherina, Ranavalona II, and Ranavalona III. Incidentally, all three of them married him.
 * The House of Stuart traces their lineage from an ancestor who named himself "Stewart" because he was hereditary steward of the Scottish throne. (This may have been the inspiration for the Tolkien example noted above.)