History Main / HeirInLaw

* ''Manga/{{Shigurui}}'':
** Iwamoto Kogan, founder of the fearsome Kogan-Ryu style of swordsmanship, is ever more obsessed with securing the future of his school. Much to his frustration, his only child Mie is a girl. Therefore he makes his two best students, Irako Seigen and Fujiki Gennosuke, compete for the honor of marrying Mie and inheriting the dojo. While Gennosuke genuinely admires Mie and wants to serve his master, Irako is deceitful and wants it all for himself.
** OldMaster Ichidensai Funaki didn't use to have any problem with the succession of his dojo, since he had twin sons to carry on his style, but when they are slain by Gennosuke and Irako on orders from Kogan, Ichidensai is left only with his daughter Chika. Chika is in fact a {{Ladette}} ActionGirl whose skill is mightier than any of her father's remaining male students, but tradition still requires that her father pick a husband for her and make ''him'' the heir to the dojo. As the EngagementChallenge, Ichidensai holds a "Helmet-Throwing" contest to see which student can best cut through a thrown helmet in midair. This plan runs into some snags: one is that Chika has some intersex genitalia that she doesn't want anyone to know about, leading to apprehension about her wedding night. The other is that she's got a {{Yandere}} stalker in the grotesque, toad-like ex-student Gannosuke, who starts murdering each new husband Chika gets before they can even consummate the marriage.
* Because Tendo Soun from Creator/RumikoTakahashi's ''Manga/RanmaOneHalf'' has only three daughters and no sons, there is a danger that his fine dojo will become nothing more than a legacy holding to his sons-in-law. This is his principal reason for advocating the courtship of his youngest daughter Akane to his old friend's son, Saotome Ranma: Ranma is an accomplished martial artist who would have a keen interest in keeping a thriving dojo.
** It's common {{fanon}} that Cologne is so interested in having Ranma agree to honor his AccidentalMarriage to her great-granddaughter Shampoo because she believes Ranma would make an excellent heir to her own family style.
* GenderFlipped in ''Anime/DogDays''. Clarifier declared her best friend Adelaide to be her successor as the ruler of Pastillage shortly before her death instead of her younger brother Valério. Admittedly, it's never definitively stated that Adelaide and Valério are a married couple, but it is very heavily implied.

* In the manga of ''Anime/TheVisionOfEscaflowne'', the king of Asturia has three daughters and no sons. The eldest, Marlene, is deceased and the second, Eries, refuses to marry. As such, the throne is expected to pass to the husband of the third princess, Millerna, who is currently unmarried. Oddly enough, the eldest princess was actually married with a son before her death but neither of them seems to be considered for the throne, presumably because she married the ruler of another country.
* In ''Manga/OnePiece'', Sterry, Sabo's adopted younger brother, became king of Goa Kingdom via marrying the kingdom's princess, Sarie Nantokanette, and then inheriting the throne after her father and brother mysteriously died. It's heavily implied Sterry killed his in-laws to get to the throne. Since we never see them in their kingdom, it's unknown whether Sterry does all the ruling or whether he and Sarie share power.

* This is the driving force of ''Film/{{Enchanted}}'', Queen Nerissa wants to stop her stepson, Prince Edward from marrying Giselle for fear of losing the throne to them. Though Edward would presumably be the actual ruler, Nerissa focuses all her attention on Giselle and throws all her accusations of her throne being stolen at Giselle, not Edward.

* In ''Film/CurseOfTheGoldenFlower'' the Emperor is heavily implied to be this. He was a brilliant and recently widowed general who appeared to marry the previous emperor's only daughter, the now Empress. [[spoiler: But he had to get rid of his beloved first wife to do so]].

* In Sean Russell's ''Literature/TheInitiateBrother'', Nishima is not only the most visible heir to the previous imperial dynasty, she's the ward of a powerful lord who is not on good terms with the current one. As such, she's an obvious focus for discontent, and the general assumption is that whoever marries her will be put forward as a challenger to the Emperor with her lineage as an excuse. By the end of the story, however, Nishima has actually become Empress in her own right, unmarried.

* ''Literature/ASongOfIceAndFire'':
** Ramsay Snow has used marriage twice to acquire (or legitimise his acquisition) of power. One of these instances utilizes trickery -- he claims to be married to Arya Stark, strengthening his position in the lands the Starks used to rule, but in fact, the girl in question is not Arya Stark at all but is actually Jeyne Poole posing as Arya.
** Lord Tywin's desire for Tyrion to go through with a marriage to another member of the Stark family, Sansa, has a similar rationale. Robb Stark goes so far as to disinherit Sansa to stop her marriage from being used as an excuse for House Lannister to rule the North.
*** Ironically, this trope once applied to the Lannisters themselves. When an old Lannister king died without male heirs, his son-in-law took the Lannister surname and was crowned as the first King of the Rock (the old royal title of the Lannisters before the Conquest) of Andal descent.
*** There is also the tale of the Lannister's mythical progenitor Lann the Clever, who originally took the Rock from the Casterlys (now only remembered for the name Casterly Rock). While folklore attributes the feat to many elaborate scams, they all boil down to "impregnating and marrying the last Lord's daughter."
** Alys Karstark runs away from home to Castle Black in order to prevent herself from being married to her EvilUncle who wants to inherit her title and home, the Karhold, when her brother dies (an event which they don't intend to be very far off) and who she fears will murder her as soon as she gives him an heir. Alys agrees to marry the Magnar of Thenn in an alliance brokered by Jon Snow, which he does to save Alys from her EvilUncle (who comes after her to carry her off against her will) and so she can retake her home, the Karhold. They form a new house -- House Thenn.
** Generally in this verse, however, an in-law is not considered a "full" heir but receives the title of Lord Protector. This is a regential title that allows one to rule until an heir who is related by blood to the ruling house matures. There are two Lords Protector in the books, Petyr Baelish of the Vale and Ser Bronn of the Blackwater.
* ''The Bishop's Heir'' (one of the ''Literature/{{Deryni}}'' books) features a king who, troubled by rebellion in one of the territories he rules, tries to resolve it by marrying the heir of its former rulers (whether she wants it or not). It doesn't really go according to plan. Somewhat unusual for this kind of story, the person insisting on the marriage is the protagonist.
* ''Literature/TheRiftwarCycle'' has two cases where the marriage-causes-demotion variant is relevant:
** In the ''Empire Trilogy'', Mara is the UnexpectedSuccessor to the leadership of House Acoma, but for political and social reasons, it's expected that she will marry someone and transfer lordship to him, especially because of her youth. She chooses a well-connected but easy-to-manipulate husband, which works for a while, but his abusiveness and incompetence eventually prompts her to navigate him into a situation where he publicly loses honour and has to [[{{Seppuku}} kill himself]], reverting formal control back to her. She later has other romantic arrangements, but makes a point of only ever taking a consort (who has no claim on her family titles) rather than a husband. [[spoiler:In the final book, she marries her second son to the daughter of the recently murdered Emperor to restore stability to the Empire in the aftermath of Ichindar's murder.]]
** In the ''Riftwar Saga'', the relationship between Tomas and Queen Aglaranna of the elves is of worry to the latter's people, since they think he might try to make himself king through it. In the end, however, he just becomes her consort, and her child from a previous marriage remains heir.
* ''Literature/ABrothersPrice'' contains a [[GenderFlip gender-flipped]] version, owing to the setting's GenderRarityValue. Society is matriarchal, but a father with royal blood confers status, and the protagonist is kidnapped to be such.
* In ''Literature/KingsQuestTheFloatingCastle'' (part of the ''VideoGame/KingsQuest'' franchise), a villain is keeping an underage princess prisoner in order to ensure he's the one to marry her [[JailBaitWait when she's old enough]].
* In Fiona [=McIntosh=]'s ''Quickening'' trilogy, King Celimus tries to put the queen of a neighbouring kingdom in a position where she has little option but to marry him. Naturally, he's not intending to rule together with her.

* {{Engagement Challenge}}s in ''Literature/TalesOfTheFiveHundredKingdoms'' work this way. Most of the winners are of royal blood themselves, but the King of Otraria (from ''The Fairy Godmother'') was born common and elevated to crown prince when he married the princess.
* In ''Literature/TheQueensThief'' series, the Queen of Attolia was a minor princess whose fiancé plotted to take the throne by killing her brother, the heir. Once that was done, the fiancé would seize power through her, except that he and his father [[TooDumbToLive discussed these plans around her openly]], so she poisoned him at their wedding and took the throne herself. However, because Attolia is pretty sexist, the country remained unstable so long as her barons thought they could marry her and seize power themselves, forcing her to enact a brutal regime [[spoiler:until she married Eugenides, who puts in enough kinging that she can maintain her rule without a problem]].

* ''Literature/{{Dune}}'': The Bene Gesserit's initial plan was to ensure the current Emperor only had daughters[[note]]they are capable of controlling the sex of their offspring[[/note]], and then marry one of them to the Kwisatch Haderach, TheChosenOne and end product of their millennia-long breeding program, so they could have control over the throne. When events result in the Kwisatch Haderach -- now Paul -- being born a generation early, Paul hijacks the plan, marries the Emperor's daughter, and becomes Emperor himself, to their great dismay.
* ''Literature/TheCourtshipOfPrincessLeia'': This is {{gender flip}}ped from the usual examples. A man [[{{Matriarchy}} cannot inherit]] the throne of Hapes personally, but his wife becomes Queen. Prince Isolder thus comments how in a way he has ultimate power due to this, as it's his choice who succeeds his mother. Leia internally dismisses this as a rationalization.
* This is [[spoiler:initially]] the case for Princess Yumina Urnea Belfast in ''Literature/InAnotherWorldWithMySmartphone''. (A male cousin would've been higher in the line of succession, but Yumina only had a single female cousin.) As such, her parents are eager to push her into an ArrangedMarriage with main protagonist Mochizuki Touya after he foils an assassination plot on the King's life (and passes a SecretTestOfCharacter via Yumina's [[MagicEye Mystical Eyes]]). Touya is initially hesitant about marrying Yumina, but she eventually grows on him ([[MarryThemAll as do his other eventual fiancées]]), but he has no interest in ruling the Kingdom of Belfast. [[spoiler:Later in the light novels, this last point is subverted twice, as the King and Queen of Belfast eventually have a son to take over as the Crown Prince, while Touya himself becomes the ruler of a small Duchy that's established for him.]]
* [[PlayingWithATrope Played with]] several times in ''Literature/HowARealistHeroRebuiltTheKingdom'':
** Before the story starts, Albert becomes king of Elfrieden because he married the [[SuccessionCrisis only surviving member of the royal family]]. His wife, Elisha, could take the throne, but the royal family is so controversial that putting someone else on the throne is safest.
** Souma is given the throne directly by Albert, but he is still engaged to Liscia, the princess, to give the abdication more legitimacy. Souma later also takes over Amidonia and again gets legitimacy by marrying Roroa, princess of that country, after she overthrew her brother Julius in a coup.
** After being driven out of his country, Julius Amidonia marries the princess of the Kingdom of Lastania, and he's set to become the next king rather than Tia Lastania taking the throne. It's unclear if this is because the monarch has to be male or if Tia just doesn't want to rule.
* ''Literature/WiedergeburtLegendOfTheReincarnatedWarrior'': GenderFlipped in the {{backstory}}. Empress Hilda of Nevaria requested the right to marry the former Emperor of Nevaria's son as her prize for winning the Grand Spiritualist Tournament. The Emperor later abdicated the throne to her, and she's been TheHighQueen ever since.
* ''Literature/EndoAndKobayashiLive The Latest on Tsundere Villainess Lieselotte'': Originally, this is what Marquis Bruno Riefenstahl plans for his distant nephew Baldur that Baldur will inherit the marquessate from Bruno, conditioned on Baldur marrying one of Bruno's several daughters. However, since it's revealed [[spoiler:Fiene is the illegitimate and only child of Bruno's older brother]], she was named the heir to the position of the head of the Riefenstahl household, but the position of the marquis will fall to her husband.
* ''Literature/{{Everland}}'': In ''Ozland'', part of Katt's plan to become Queen of Germany involves marrying Prince Jack, as she knows the populace won't accept her, a foreigner, as ruler otherwise.
* ''Literature/TheChroniclesOfDorsa'': This is mentioned as one option for Emperor Andreth-his future son-in-law could become his heir. However, he ends up instead making his daughter heir. That's because making his son-in-law heir would entail his adoption into House Dorsa as a full son. Since Princess Tasia, his daughter, has been targeted for assassination, they risk adopting a man who's involved with the plot. [[spoiler:Tasia later lets her husband Mace take the throne after she's believed dead.]]

* In ''[[VideoGame/KingsQuestVIHeirTodayGoneTomorrow King's Quest VI]]'', the [[EvilChancellor Evil Vizier]] has killed the king and queen and is trying to force their daughter to marry him. He doesn't care about the real princess, being willing to achieve his ends with a shapeshifting genie if required. In the end, the hero marries the princess instead.

* In ''VideoGame/CrusaderKings'' the downplayed trope is very common, as characters get a prestige bonus from marrying landed characters or their close relatives (whether they are set to inherit or not). Otherwise this trope is averted as females either can't inherit at all (under completely agnatic systems) or inherit fully as rulers (agnatic-cognatic or fully cognatic systems) with whoever they marry being their spouse and nothing more or less. It is possible to marry female rulers in order to put ''your dynasty'' on the throne from the next generation onwards (and is the norm) but ''your character'' does not gain any influence in your spouse's realm simply by marrying her (until they die and you start playing their heir, at any rate).
* In ''VideoGame/AlQadimTheGeniesCurse'', the Caliph's daughter is due to marry a son of the Al-Hazrad family (you, the protagonist). However, the Al-Hazrads' genie nearly drowns the Caliph in a storm, and he decides that his soon-to-be in-laws aren't content with just securing the marriage -- they want him out of the way so that they could seize the throne. The Caliph accepts that you were ignorant of the plot yourself, since you helped rescue him, but the other Al-Hazrads are imprisoned.
* This is the point of the Throne of Miscellania quest in ''VideoGame/RuneScape''; in order to become the prince/princess regent of Miscellania, the king, Vargas, requires you to marry his son, Prince Brand (as a female player) or daughter, Princess Astrid (as a male player). It is downplayed, however, since you only have to get engaged to the royal child in order to become regent and you never actually have to marry them. Though you can marry them later on, it's your choice and will not affect your regency if you don't [[spoiler: and you remain regent even after they die]].
* Discussed in ''VideoGame/JadeEmpire''; Silk Fox fears that Death's Hand will try to convince her father to invoke this trope on her. [[spoiler: she's wrong, for a number of reasons.]]
** This happens to the player themself if you romance Silk Fox. Though, the text suggests you're more of a RulingCouple.
* The GoldenEnding of ''VideoGame/PrincessMaker'' has this happen with the daughter marrying the prince and being chosen by the king to succeed him to the throne as queen regnant.
* King Irwin ([[TheHero the Luminary's]] father) in ''VideoGame/DragonQuestXI'' married into the royal family of Dundrasil, [[BodyguardCrush having previously been the head of the princess' personal guard]].

* ''VideoGame/FateGrandOrder'': Adamska Violet is the current boss of the Violet Family which he married into. The fiancé of his eldest daughter Juliet would be next heir of the Violet Family due to Cain, the only son, being mentally handicapped and unsuited for the leadership role. [[spoiler:After all potential marriage candidates of Juliet ended up murdered, Cain steps forward and reveals to his family that he was not mentally handicapped at all and that he will take responsibility as the heir of the Violet Family and Goldie Family (due to his engagement between him and the Goldies' daughter Lorie).]]

* Much like in the comics, the two-part episode "[[Recap/BatmanTheAnimatedSeriesS1E60TheDemonsQuestPart1 The Demon's]] [[Recap/BatmanTheAnimatedSeriesS1E61TheDemonsQuestPart2 Quest]]" of ''WesternAnimation/BatmanTheAnimatedSeries'' has a weakened Ras al Ghul holding out for Batman to marry him off to his daughter Talia as he deems him a worthy heir. In contrast to other examples Talia in this version actually supports that plan. Much like in the comics, Batman refuses the offer.

* In a vaguely posthumous example, the pagan (or possibly Orthodox) Didysis Kunigaikštis (Grand Duke) [[https://en.wikipedia.org/wiki/W%C5%82adys%C5%82aw_II_Jagie%C5%82%C5%82o Jogaila Algirdaitis of Lithuania]] was baptized into the Catholic Church as Władysław at age 24 (minimum), married off to Królowa [[SheIsTheKing (King)]] [[https://en.wikipedia.org/wiki/Jadwiga_of_Poland Jadwiga Andegaweńska]] (who was [[AChildShallLeadThem 12, max]]), and ruled Poland for the rest of his life; outliving both Jadwiga who [[DeathByChildbirth survived her only child by mere days]] but the latter's second cousin Anna of Cilli (a fellow great grand-child of Polish King [[https://en.wikipedia.org/wiki/W%C5%82adys%C5%82aw_I_%C5%81okietek Władysław I Łokietek]]) and ''her'' offspring. And his third wife, Elżbieta Granowska. It was the wife number ''four'', Sofja/Sonka, born to the Ruthenized Ltithuanian house of Alšėniškiai/Гальшанскі, from whom the Jagiellonian dynasty traced their descent.

* In a vaguely posthumous example, the pagan (or possibly Orthodox) Didysis Kunigaikštis (Grand Duke) [[https://en.wikipedia.org/wiki/W%C5%82adys%C5%82aw_II_Jagie%C5%82%C5%82o Jogaila Algirdaitis of Lithuania]] was baptized into the Catholic Church as Władysław at age 24 (minimum), married off to Królowa [[SheIsTheKing (King)]] [[https://en.wikipedia.org/wiki/Jadwiga_of_Poland Jadwiga Andegaweńska]] (who was [[AChildShallLeadThem 12, max]]), and ruled Poland for the rest of his life; outliving both Jadwiga who [[DeathByChildbirth survived her only child by mere days]] but the latter's second cousin Ana Celjska (a fellow great grand-child of Polish King [[https://en.wikipedia.org/wiki/W%C5%82adys%C5%82aw_I_%C5%81okietek Władysław I Łokietek]]) and ''her'' offspring. It was wife number four Sofja/Sonka, born to the Ruthenized Ltithuanian house of Alšėniškiai/Гальшанскі, from whom the Jagiellonian dynasty traces their decent.

** William III became King of England, Scotland, and Ireland through his marriage to Mary II, initially as co-monarch rather than sole monarch. However, he continued to rule after her death rather than make way for her heirs, as he would have done had he just been a consort. It probably helped that William was also the next male in the line of succession as Mary's [[KissingCousins first cousin]], and that he took the throne in what was essentially a coup d'etat (Parliament basically issued him a very polite engraved invitation to come and "invade" the country, as they didn't like his uncle/father-in-law King James II setting up a Catholic dynasty).

*** At the same time, it was made clear his children would only succeed if they were also ''Mary's'' children; if they failed to have children or their children predeceased them (which they did), the throne would (and eventually did) pass to Mary's sister, Anne, even if William had remarried and had children by another wife (though he never did) because Anne, plus any surviving children she had (as it happens, they all predeceased both her and William) would have still been considered higher in the succession (as Mary's sister and nephews/nieces) than any child of William's by another woman (who would be her first cousins-once-removed).

* Francis I, who was the Duke of Lorraine and Bar and the Gran Duke of Tuscany, officially became the Holy Roman Emperor and Archduke of Austria after marrying Maria Theresa in 1745. It was decided that Salic Law prevented a female ruler of the Holy Roman Empire which led to the War of Austrian Succession. To resolve the conflict, Maria Theresa married Francis and he was elected Emperor. In reality, Maria Theresa was the ruler, and she is remembered as Empress while Francis is mentioned less often.

* Because Tendo Soun from Creator/RumikoTakahashi's ''Anime/RanmaOneHalf'' has only three daughters and no sons, there is a danger that his fine dojo will become nothing more than a legacy holding to his sons-in-law. This is his principal reason for advocating the courtship of his youngest daughter Akane to his old friend's son, Saotome Ranma: Ranma is an accomplished martial artist who would have a keen interest in keeping a thriving dojo.