History Main / HeirInLaw

* 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.

** 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. 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 doesn't marry and keeps her position.
** 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 relationship remains heir.

* ''Series/{{Arrow}}: Similar to his plans with ComicBook/{{Batman}} in the comics, Ras al Ghul wants to make Oliver Queen his successor and heir as leader of the League Of Assassins after the latter survived their first battle. For doing so he marries Oliver to his daughter Nyssa. [[spoiler: It backfires as Oliver has no interest in leading the League, just wanting to get close to Ras to kill him. Malcolm Merlyn ends up leading the League, despite having no familiar bond to the original Ras at all.]]

* ComicBook/RasAlGhul has tried to offer heirship to his criminal empire to both ComicBook/{{Batman}} and ComicBook/{{Bane}} by way of marriage to his daughter ComicBook/TaliaAlGhul, mostly due to him finding her a [[HeirClubForMen poor heir to him due to her gender]]. It didn't work out in either case.

* In the manga of ''Anime/VisionOfEscaflowne'', 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.

* This is [[spoiler:initially]] the case for Princess Yumina Urnea Belfast in ''LightNovel/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.]]

* In Disney's ''WesternAnimation/{{Aladdin}}'', this the plan of Jafar, the EvilChancellor. By using his magic on the Sultan, he plans to secure a marriage to Princess Jasmine, the sultan's daughter, and gain the throne through his marriage to her. It doesn't seem that he intends for his new wife to live long after his ascension.

** In ''WesternAnimation/{{Shrek}}'', Lord Farquaad wanted to marry Princess Fiona solely because it would make him a king. When he discovers Fiona's curse, he plans to keep her locked away and never be seen again. Unfortunately for him, his reign doesn't last too long before he becomes dragon food.

[[folder: Western Animation]]

[[folder: Real Life]]

* The first Roman emperor, UsefulNotes/{{Augustus}}, had no sons, only a daughter Julia. He tried to marry her to handpicked successors, but the first one (Marcellus) died. The second one, Marcus Agrippa, also died, but not before they had 3 sons (and 2 daughters). However, two of those died young and the third was exiled for unclear reasons. By then, Augustus was married to Livia, who had an adult son, Tiberius, from her first marriage. The problem was, Tiberius was already married. Augustus ordered him to divorce his wife, marry Julia, and become his heir. Both Tiberius and Julia hated each other, and after her extramarital affars became known, she was exiled. Tiberius ended up becoming emperor.

* Following the sudden death of [[UsefulNotes/CarolusRex King Karl XII of Sweden]] at the Siege of Fredriksten in 1709, his sister Princess Ulrika Eleonora inherited the throne since Karl had refused to marry until all his enemies were defeated. Ulrika abdicated to her husband Frederick Hesse-Kassel, Karl's brother-in-law, two years later.

*** 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 would have still been considered higher in the succession (as Mary's sister) than any child of William's by another woman (who would be her first cousins-once-removed).

** Later on in history, Albert was the Prince Consort of Queen Victoria, but [[http://en.wikipedia.org/wiki/Regency_Acts#Regency_Act_1840 Parliament passed a law]] to prevent him from repeating William's actions. Not that it mattered--they had nine children, all of whom survived, and Prince Albert died in December 1861 at the age of 42, leaving Victoria a widow (and [[WidowWoman conspicuously so]]) for the rest of her long reign (just over 39 years after Prince Albert's death).

** Later on in history, Albert was the Prince Consort of Queen Victoria, but [[http://en.wikipedia.org/wiki/Regency_Acts#Regency_Act_1840 Parliament passed a law]] to prevent him from repeating William's actions.

* ''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.

* This trope, together with AdultAdoption, is commonly used in Japan, where it is called [[https://en.wikipedia.org/wiki/Mukoyōshi Mukoyōshi]].
** Not a royalty example[[note]]Given how common AdultAdoption is in Japan, emperors are expressly ''forbidden'' to adopt[[/note]], but when Kinjiro Miyaki married neighbor Yae Kimura, his wife's family lacked a male heir, so he changed his name to [[https://en.wikipedia.org/wiki/Jiroemon_Kimura Jiroemon Kimura]], effectively being adopted by his in-laws to carry on the family. Kimura later became known for being the oldest man whose age is fully verified, living to 116 years and 54 days.

* Not a royalty example, but when Kinjiro Miyaki married neighbor Yae Kimura, his wife's family lacked a male heir, so he changed his name to [[https://en.wikipedia.org/wiki/Jiroemon_Kimura Jiroemon Kimura]], effectively being adopted by his in-laws to carry on the family. Kimura later became known for being the oldest man whose age is fully verified, living to 116 years and 54 days.

Similar things occur with royal [[WidowWoman widows]]. Another variant is when instead of the husband claiming the throne directly, he becomes regent to a son who he [[ChosenConceptionPartner produced with his chosen princess]] for that purpose. A downplayed version is where the husband isn't actually going to inherit anything through the marriage but thinks lineage makes for a good TrophyWife.

[[folder:Anime and Manga]]

[[folder:Fanfiction]]

[[folder:Film - Animated]]

[[folder:Film - Live Action]]

[[folder:Religion and Mythology]]

* 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 Lithuanian house of Alšėniškiai/Гальшанскі, from whom the Jagiellonian dynasty traces their decent.

* In [[Myth/ClassicalMythology Greek mythology]], Menelaus, prince of Mycenae, becomes king of Sparta through marriage to princess Helen after her stepfather and brothers die. Thus he also had a political motive for [[UsefulNotes/TheTrojanWar getting Helen back]], since she was the justification for his own position. Helen is also the daughter of Zeus and in [[Literature/TheOdyssey]]it is stated that after death Menelaus will go to the Elysian Fields solely by virtue of being Zeus' "son-in-law.'

Similar things occur with royal [[WidowWoman widows]]. Another variant is when instead of the husband claiming the throne directly, he becomes regent to a son who he [[ChosenConceptionPartner produced with his chosen princess]] for that purpose. A downplayed version is where the husband isn't actually going to inherit anything through the marriage, but thinks lineage makes for a good TrophyWife.

[[folder: Anime and Manga]]
* ''Manga/{{Berserk}}'': The king of Midland has only one child, Princess Charlotte, and whoever marries her will become the kings' heir. Griffith, an ambitious commoner who hopes to get a kingdom of his own, works hard to impress the king with repeated victories in battle, while at the same time using all his charm to sweep the [[TheIngenue naive]] princess off her feet. Since Charlotte is not yet engaged the king's brother Count Julius and Julius's son Adonis are actually second and third in line, [[spoiler:but Griffith manages to eliminate them after Julius's unsuccessful attempt on Griffith's life]]. After winning the hundred year war for Midland, [[spoiler:Griffith blows his chance when he has a FreakOut over Guts leaving the band of the Hawk, and gets himself imprisoned and tortured by the king for deflowering Charlotte. Charlotte helps Griffith's followers to spring him out of prison, and has no choice but to say goodbye.]] Then come the Millennium Falcon Arc, [[spoiler:Emperor Ganishka invades Midland and intends to legitimize his conquest by forcing Charlotte to bear his children. Griffith miraculously returns to rescue Charlotte and all of Midland, with them being none the wiser about the DealWithTheDevil Griffith made in the Eclipse. Now a VillainWithGoodPublicity, Griffith is once again set to marry Charlotte and make his kingship official]].

** OldMaster Ichidensai Funaki didn't used 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.

* In ''Manga/DrStone'', the position of Village Chief is gained by winning a fighting tournament and then marrying the Village Priestess, who is always the daughter of the chief and previous priestess. This is important in the early part of the manga, as the strongest warrior in the village, Magma, is a {{Jerkass}} who doesn't care for the current priestess, Ruri and just wanted the throne. This motivates the various members of the Kingdom of Science, most of whom are close to Ruri, to join the tournmanent in order to save her. [[spoiler: In the end, Senku wins but immediately divorces her, both for the sake of Chrome, who he knows loves her, and because [[CelibateHero he doesn't want to be married]], though he still becomes village chief after curing her pneumonia.]]
* In the manga of ''Anime/VisionOfEscaflowne'', 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 seem to be considered for the throne, presumably because she married the ruler of another country.

** Sabo's biological parents and Sterry's adoptive parents meant for Sabo to marry Sarie Nantokanette, however Sabo's rebellious streak and apparent death nixed those plans, so they invested into adopting a higher ranking noble child.

[[folder: Comic Books]]
* ComicBook/RasAlGhul has tried to offer heirship to his criminal empire to both ComicBook/{{Batman}} and ComicBook/{{Bane}} by way of a marriage to his daughter ComicBook/TaliaAlGhul, mostly due to him finding her a [[HeirClubForMen poor heir to him due to her gender]]. It didn't work out in either case.

[[folder: Fanfiction]]

* Discussed in ''Fanfic/ASongOfIceFireAndHeart'' when King Robert Baratheon decides to name his daughter Myrcella his successor and the future Queen on the Iron Throne. When his friend Ned points the Westerosi lords will expect from her betrothed Roxas to rule in her stead, Robert is fully aware of the teenager's distaste for the trappings of royalty and admits Myrcella will likely care for the administrative part -- the bulk of day-to-day ruling -- while Roxas will happily hunt monsters and outlaws, thus focusing on the "protector of the Realm" part.

[[folder: Film - Animated]]

[[folder: Film - Live Action]]

[[folder: Literature]]

** Ramsay Snow has used marriage twice to acquire (or legitimise his acquisition) of power. One of theses 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 being used as an excuse for House Lannister to rule the North.

** 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 a 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 unusually for this kind of story, the person insisting on the marriage is the protagonist.

** 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 by a previous relationship remains heir.

* The ''Literature/{{Deverry}}'' books feature a case where, upon the death of a king, his three mutually antagonistic sons-in-law make bids for power. They stop short of proclaiming themselves kings, but do advance claims to be regent for the "rightful" king, their own respective sons (the old king's grandsons). A son of the eldest daughter ''should'' have inherited, and might have if her husband's clan were better politicians.

[[folder: Live Action TV]]

[[folder: Religion and Mythology]]
* Historically, UsefulNotes/TheProphetMuhammad had no living sons, but had at least one daughter, Fatima. Fatima was married to Ali, [[KissingCousins Muhammad's cousin]], and according to Shiite Muslims, he was Muhammad's proper heir, followed by their sons (who were, of course, Muhammad's grandsons). Different branches continue to follow Ali's descendants, whether they're still around (Ismailis/"Seveners") or a MessianicArchetype believed to currently be in hiding. {{Averted}} by Sunni Muslims, who don't believe that leadership of the Muslim community has to be hereditary.

[[folder: Video Games]]

* 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 no). 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 the you were ignorant of the plot yourself, since you helped rescue him, but the other Al-Hazrads are imprisoned.

* ''VideoGame/YesYourGrace'': Succession works that way in the game's setting. At some point, it's explictly stated that since the PlayerCharacter doesn't have a son, the next-in-line for his throne is his son-in-law. This can be fixed by him having a new child and arranging for it to be a boy.

[[folder: Visual Novels]]
* This is the norm in ''VisualNovel/TheConfinesOfTheCrown'', with it being a matter of law that sons-in-law take precedence even over actual sons. Marrying an eldest daughter makes you heir, while the sons who would be heirs in a more traditional set-up have to go princess-hunting in the hopes of becoming king of somewhere that way.

* In ''WesternAnimation/TheFairlyOddParents'', this is revealed to be Princess Mandie's reason for wanting to marry Mark Chang; her plan was to marry Mark, get rid of his father and then set Mark aside, so she could be the queen of both their worlds and used the combined strength of both to conquer the universe. The plan would have succeeded, but luckily for Mark, [[BabysitterFromHell Vicky]] put a stop to it out of love for Mark.

* Formal, codified systems of royal inheritance tend not to use this idea--those which don't let princesses inherit tend to send the throne to a male cousin (who does have [[BlueBlood royal blood]]) rather than sending it to a princess's husband (who doesn't). That said, plenty of people have pressed claims based on their marriages anyway, and if they had the bigger army, sometimes got away with it. A man ''could'' legally get a title through his wife, but would hold it ''jure uxoris'' ("by right of his wife" or "in right of a wife"). Legally the husband and wife would equally hold the title, rather than the husband taking the whole thing, but sometimes he could take it in the case of her death or even divorce.

*** 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 would have still been considered higher in the succession (as Mary's sister) 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.
* This was a sore spot between Mary, Queen of Scots and her husband, Henry Stuart, Lord Darnley. While Darnley was officially the King of Scotland, with his name coming before Mary's on government documents and his face appearing on coinage, she was the queen and he the consort. Darnley was constantly badgering Mary and the Scottish Parliament to bestow him with the Crown Matrimonial, which would have allowed him to inherit the throne and rule in his own right if Mary died. Darnley's ambition to rule Scotland in place of his wife was enough that Catherine de Medici, Queen Mother of France, wondered if it affected his feelings toward his and Mary's son, whose claim to the succession trumped his.

** He was, however, fine with them having long-term relationships with his courtiers and even children with said courtiers, since neither the lovers nor their sons could claim the throne without the benefit of marriage.
* Not a royalty example, but when Kinjiro Miyaki married neighbor Yae Kimura, his wife's family lacked a male heir, so he changed his name to [[https://en.wikipedia.org/wiki/Jiroemon_Kimura Jiroemon Kimura]], effectively being adopted by his in-laws to carry on the family. Kimura later became known for being the oldest man whose age is fully verified, living to 116 years 54 days.
* In a vaguely postumous 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 Lithuanian house of Alšėniškiai/Гальшанскі, from whom the Jagiellonian dynasty traces their decent.