Heir-In-Law

Paul: And the Emperor has no sons, and his daughters are yet to marry.
Liet-Kynes: You'd make a play for the throne?

— Dune (2021)

Sometimes, royal title in a male-favouring system can't be inherited by a king's daughter, but can be inherited by the man who marries her. The throne can be passed on via a princess, but not solely to her. She'll instead be placed somewhere on a scale of royal wives—if she's lucky, perhaps as co-ruler, but if she's not, perhaps just as a convenient tool who ceases to be useful as soon as the marriage goes through. In some cases, this is even retroactive: a woman who has already inherited will be demoted to consort if she later marries.

This can be involved in a number of plots.

• The princess in question is even more likely than usual to be subject to Arranged Marriage and Altar Diplomacy. Good luck being allowed to Marry for Love when your choice will determine the future ruler of the kingdom.
• Social Climbers and other ambitious people will Compete for the Maiden's Hand, possibly through an Engagement Challenge (or by winning a Standard Hero Reward, since the princess who is usually included may come packaged with a ticket to inherit).
• The more villainous suitors may tell the princess that Now You Must Marry Me, like it or not. This can work even if the villain has already taken over the kingdom, because The Usurper may gain legitimacy by marrying the previous king's heir.
• Alternatively, a villain may simply want a princess dead so that her potential nuptials can't cause a Passed-Over Inheritance or turn someone into a Returning Rightful King.
• If the marriage greatly changes the financial situation of one of the parties, things like Nobility Marries Money and Rags to Royalty may be in play. Money, not the throne, might be someone's main motive—people may see a princess as a Meal Ticket, or an Impoverished Patrician may trade on lineage to achieve success as a Gold Digger.
• Princesses who don't know that they're princesses can still be subject to this, so when people get a Really Royalty Reveal, it may coincide with learning that someone wants them married/dead because of this trope.

Similar things occur with royal widows. Another variant is when instead of the husband claiming the throne directly, he becomes regent to a son who he 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 Trophy Wife.

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Examples:

Anime & Manga

• Berserk: The king of Midland has only one child, Princess Charlotte, and whoever marries her will become the king's 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 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, but Griffith manages to eliminate them after Julius's unsuccessful attempt on Griffith's life. After winning the hundred-year war for Midland, Griffith blows his chance when he has a Freak Out 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, 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 Deal with the Devil Griffith made in the Eclipse. Now a Villain with Good Publicity, Griffith is once again set to marry Charlotte and make his kingship official.
• 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.
  • Old Master 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 Lad-ette Action Girl 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 Engagement Challenge, 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 Rumiko Takahashi's Ranma ½ 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 Accidental Marriage to her great-granddaughter Shampoo because she believes Ranma would make an excellent heir to her own family style.
• Gender Flipped in Dog Days. 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 Dr. STONE, 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 tournament in order to save her. In the end, Senku wins but immediately divorces her, both for the sake of Chrome, who he knows loves her, and because he doesn't want to be married, though he still becomes village chief after curing her pneumonia.
• In the manga of The Vision of Escaflowne, 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 One Piece, 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.
  • 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 in adopting a higher-ranking noble child.

Comic Books

• Batman: Ra's al Ghul has tried to offer heirship to his criminal empire to both Batman and Bane by way of marriage to his daughter Talia, mostly due to him finding her a poor heir to him due to her gender. It didn't work out in either case.

Fan Works

• Gender-inverted version in She Can't Head the Family Business If She's Not Family, in which fashion mogul Gabriel Agreste has deemed his son Adrien unsuitable to inherit his company, but Marinette Dupain-Cheng, one of his classmates who likes him, has all the qualifications he needs—only she's started to fall for guitarist Luka Couffeine instead, and if she doesn't get together with Adrien, Gabriel will have trouble finding a reason to make her his apprentice and heiress. As a result, he ends up turning his efforts (both as Gabriel and as the supervillain Hawkmoth) towards making sure Adrien and Marinette end up together.
• Discussed in A Song of Ice, Fire and Heart 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 out the Westerosi lords will expect 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.

Films — Animation

• In Disney's Aladdin, this is Jafar's (the Evil Chancellor) Plan B after failing to get the magic lamp. 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.
  Iago: You marry the princess, all right? [...] Then you become the sultan! [...] And then, we drop papa-in-law and the little woman off a cliff.
• Shrek:
  • In 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.
  • It is later revealed in Shrek 2: Charming and Fiona had been betrothed so that Charming could become king. This was to repay his mother, the Fairy Godmother, for turning her father into a human so he could be with Fiona's mother. This fails as Fiona had fallen in love with Shrek and married him instead.
  • Comes up again in Shrek the Third: after King Harold dies, Shrek goes to find Fiona's cousin, Arthur, so he can avoid this trope, as he doesn't want to be stuck with royal duties. Apparently, the idea of Fiona just ruling alone never crosses anybody's mind.
  • Supplementary material reveals Harold was this; he inherited the throne by marrying Lillian, whose father was the previous king of Far Far Away.
• In The Swan Princess, Rothbart's motive for cursing Odette is blackmailing her into marrying him. This is his backup plan after he failed to take over the kingdom by force with his magic, saying that if he's the legitimate king he won't have to spend his life defending the position. (Because nobody will object to an exiled criminal suddenly marrying the recently-orphaned princess?)
• This is the driving force of 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.

Films — Live-Action

• In Aladdin (2019), Jasmine is constantly refusing suitors because she wants to avert this trope and rule as Sultana in her own right, much to the displeasure of male politicians who want her to Stay in the Kitchen. Jafar later tries to invoke this by blackmailing Jasmine into marrying him to legitimize his overthrow of her father. In the end, Jasmine gets her wish when her father abdicates and lets the succession devolve upon her, at which point she takes Aladdin as her consort.
• Dune: Part Two: In the first film Paul muses that Shaddam has no male heirs, so whoever marries Irulan (or one of her sisters) will be the next Emperor, rather than Irulan ruling in her own right. At the end of the movie, Irulan accepts to become Paul's wife in exchange for her father's life.
• Terry Gilliam's film version of Jabberwocky has Dennis given this as his Standard Hero Reward, although he doesn't actually want it. He has an Unrequited Love for his peasant neighbour Griselda, who is generally unpleasant to him.
• In Maleficent, Stephan becomes king by marrying the former king's daughter. She doesn't rule and barely even has a presence in the story.
• In Curse of the Golden Flower 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. But he had to get rid of his beloved first wife to do so.

Literature

• In Sean Russell's The Initiate Brother, 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.
• The Children of the Black Sun trilogy features confusion between a culture where this can happen and one where it can't. Mira is the daughter of a clan chief, and a Mesentreian noble thinks that bargaining with the clan to marry her is the same thing as securing eventual rulership for himself. Ricalani clans don't actually work like that, and all he'd get out of the marriage is Mira herself, but unfortunately for Mira, her clan is quite happy to take advantage of his misunderstanding and strike a deal.
• A Song of Ice and Fire:
  • 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 Evil Uncle 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 Evil Uncle (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 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.
• The Riftwar Cycle has two cases where the marriage-causes-demotion variant is relevant:
  • In the Empire Trilogy, Mara is the Unexpected Successor 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 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. 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.
• A Brother's Price contains a gender-flipped version, owing to the setting's Gender Rarity Value. Society is matriarchal, but a father with royal blood confers status, and the protagonist is kidnapped to be such.
• In King's Quest: The Floating Castle (part of the King's Quest franchise), a villain is keeping an underage princess prisoner in order to ensure he's the one to marry her 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.
• The 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.
• Engagement Challenges in Tales of the Five Hundred Kingdoms 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 The Queen's Thief 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 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 until she married Eugenides, who puts in enough kinging that she can maintain her rule without a problem.
• This is the plan in The Horse and His Boy. A Calormene prince wants to marry Queen Susan of Narnia so he'll be able to take over the country. That he has the hots for her doesn't hurt.
• The entire plot of Kingdom River is driven by this.
  • Queen Joan of the Middle Kingdom has only one child, Princess Rachel, who is more interested in books and learning than ruling a kingdom. Because of this, various River lords want to marry her to get to the throne. Joan wants to find a son-in-law who will be strong enough to hold the throne and keep the lords in check, but who's also patient enough to wait for the throne, rather than kill her to get to it immediately and who will actually care about her daughter, rather than kill or abandon her once they have the throne. For this reason, she reluctantly allies with the protagonist Sam Monroe, Captain-General of North Mexico, against their common enemy, Toghrul Khan, hoping he'll fulfill that need. the book ends with Sam marrying Rachel and becoming king after Joan dies in battle.
  • Queen Joan was this herself; originally queen consort, after her husband, King Newton, died, she became the reigning queen due to Rachel being a baby at the time. Unlike Rachel, she actually wanted to rule and made a point of killing off a few enemies at the start of her reign to show people she meant business.
• 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, and then marry one of them to the Kwisatch Haderach, The Chosen One 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.
• The Courtship of Princess Leia: This is gender flipped from the usual examples. A man 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 initially the case for Princess Yumina Urnea Belfast in In Another World with My Smartphone. (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 Arranged Marriage with main protagonist Mochizuki Touya after he foils an assassination plot on the King's life (and passes a Secret Test of Character via Yumina's Mystical Eyes). Touya is initially hesitant about marrying Yumina, but she eventually grows on him (as do his other eventual fiancées), but he has no interest in ruling the Kingdom of Belfast. 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.
• Played with several times in How a Realist Hero Rebuilt the Kingdom:
  • Before the story starts, Albert becomes king of Elfrieden because he married the 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.
• WIEDERGEBURT: Legend of the Reincarnated Warrior: Gender Flipped 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 The High Queen ever since.
• Endo and Kobayashi Live! 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 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.
• 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.
• The Chronicles of Dorsa: 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. Tasia later lets her husband Mace take the throne after she's believed dead.

Live-Action TV

• Arrow: Similar to his plans with 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. 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.
• In the backstory of the Korean Drama Emperor Wang Guhn, King Hunnan had two daughters but no sons, so he looked for an appropriate suitor amongst his knights who would then become king of Silla (pre-Korea Korea). The one chosen actually prefers the younger daughter, but he marries the older daughter because that's the only way he'd become king.

Mythology & Religion

• Historically, The Prophet Muhammad had no living sons but had at least one daughter, Fatima. Fatima was married to Ali, 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 Messianic Archetype believed to currently be in hiding. Averted by Sunni Muslims, who don't believe that leadership of the Muslim community has to be hereditary.
• Historically, many prominent rabbis bestowed their positions to their sons-in-law. Rebbe Menachem Mendel Schneerson, last leader of the Lubavitch Chassidic movement, is one particularly notable example of this trope from modern times.
• In 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 getting Helen back, since she was the justification for his own position. Helen is also the daughter of Zeus and in The Odyssey it is stated that after death Menelaus will go to the Elysian Fields solely by virtue of being Zeus' "son-in-law.'

Video Games

• In King's Quest VI, the 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.
• Dragon Age: Origins features Anora, the king's widow. It's a semi-Elective Monarchy, so marrying Anora doesn't automatically grant rulership, but it would provide a public relations bonus and a sense of continuity. It's possible for her to become co-monarch with her late husband's half-brother, joining their respective claims. Player characters who are noblemen can talk Anora into marriage themselves, but lacking royal blood, they only get to be Prince-Consort. (A third option just has Anora become queen regnant in her own right, without remarrying at all.)
• At the end of Final Fantasy Tactics, the winner of the Succession Crisis known as the War of the Lions marries the daughter of the late king to establish legitimacy for a crown he'd won by virtue of military might and Chronic Backstabbing Disorder. The princess, unable to trust her husband because of his Chronic Backstabbing Disorder, tries to knife him, and is killed in self-defense.
• This is very common in Fire Emblem epilogues, especially those with modular pairings via Relationship Values. But it's most notable in Fire Emblem: Genealogy of the Holy War, which devotes an entire Modular Epilogue to who inherits which nation as the two generations of conflict kills off much of the former ruling families. One of its most notable examples is Erinys, a simple Pegasus Knight with no noble blood, canonically becoming Queen of Silesse during the Time Skip through her marriage to Lewyn.
• In The Legend of Zelda: Four Swords, the plan to take over the kingdom begins with kidnapping Princess Zelda for marriage purposes.
• In Valkyria Chronicles, Prince Maximillian's plan to take over Gallia involves forcing its princess to marry him.
• In Crusader Kings 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 Al-Qadim: The Genie's Curse, 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 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 and you remain regent even after they die.
• Discussed in Jade Empire; Silk Fox fears that Death's Hand will try to convince her father to invoke this trope on her. 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 Ruling Couple.
• The Golden Ending of Princess Maker 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 (the Luminary's father) in Dragon Quest XI married into the royal family of Dundrasil, having previously been the head of the princess' personal guard.
• Yes, Your Grace: Succession works that way in the game's setting. At some point, it's explicitly stated that since the Player Character 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.
• Fate/Grand Order: 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. 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).

Visual Novels

• This is the norm in The Confines of the Crown, 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 somewhere that way.

Western Animation

• In The Fairly OddParents!, 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, Vicky put a stop to it out of love for Mark.

Real Life

• Formal, codified systems of royal inheritance tend not to use this idea—those who don't let princesses inherit tend to send the throne to a male cousin (who does have 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.
• The first Roman emperor, 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 to Agrippa's daughter from an earlier marriage. 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.
• Specific examples from English history:
  • 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 heir (her sister Anne), 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 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 (which they did) or their children predeceased them, 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).
  • A downplayed example in the case of the Tudor claim to the throne of England and France; the Tudors already had their own claim to the throne, as descendants of the House of Lancaster, but it was weak. Henry VII's marriage to Elizabeth of York (heiress to the previous royal lineage) as well as the marriage by Princess Katherine of France (widow of Henry V) to Owen Tudor (Henry's grandfather) helped strengthen their claim, though it was primarily enforced by right of conquest.
    • Indeed, Henry VII seemed to be aware of this trope and made a point of being crowned before his marriage to her to make it clear he was king by his own efforts, not by being Elizabeth's husband.
  • The negotiations that preceded the marriage of Mary I of England and Philip of Spain were intended to ease English fears that this trope would hand ownership of England over to the Habsburgs. Under common law of the time, any property and titles held by a woman became her husband's upon marriage. Parliament demanded that Philip only receive the title of King of England for the duration of Mary's life, with no right to succeed her.
  • Later on in history, Albert was the Prince Consort of Queen Victoria, but 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 conspicuously so) for the rest of her long reign (just over 39 years after Prince Albert's death).
  • This is most likely why Eleanor, the Fair Maid of Brittany, was kept imprisoned for her entire life; after the death of her brother, Arthur, she was technically the rightful heiress to the Plantagenets' vast holdings and a potential husband might have tried to press her claim.
  • Similar to the above example, Princesses Gwenllian and Gwladys of Wales, the daughters of the last two independent Princes of Wales, were both placed in convents at a young age after their fathers' defeat to prevent the possibility of potential husbands claiming the throne through them.
• Frederick II, Holy Roman Emperor, inherited or was elected to many titles in his own right, but claimed the title King of Jerusalem by virtue of marrying Yolande, the heir of the Crusader States. Yolande was very young and not acting as ruler in her own right. What power she had in her name was exercised by her father John, acting as Regent. Upon their marriage, Frederick immediately declared himself in charge of her territory and dismissed her father. Yolande never reached adulthood—she lived only long enough to give birth to an heir and die in the process.
• Francis I, who was the Duke of Lorraine and Bar and the Grand 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.
• In addition to being King of Aragon in his own right, the Catholic Monarch Ferdinand was King of Castile (or co-monarch) by virtue of his marriage to Isabella of Castile. Their daughter, Joanna of Castile (called Joanna the Mad) married the Habsburg Philip of Burgundy (Philip the Handsome) who was recognized as King of Castile and was effectively the king of Spain.
• This is most likely why Holy Roman Emperor Charlemagne never let his daughters marry; he feared their husbands might challenge him or his sons one day for the throne. It had happened to other rulers from his line, so it was a reasonable fear.
  • 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.
• This trope, together with Adult Adoption, is commonly used in Japan, where it is called Mukoyōshi.
  • Not a royalty example^note Given how common Adult Adoption is in Japan, emperors are expressly forbidden to adopt, but when Kinjiro Miyaki married neighbor Yae Kimura, his wife's family lacked a male heir, so he changed his name to 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.
• In a vaguely posthumous example, the pagan (or possibly Orthodox) Didysis Kunigaikštis (Grand Duke) Jogaila Algirdaitis of Lithuania was baptized into the Catholic Church as Władysław at age 24 (minimum), married off to Królowa (King) Jadwiga Andegaweńska (who was 12, max), and ruled Poland for the rest of his life; outliving both Jadwiga who survived her only child by mere days but the latter's second cousin Ana Celjska (a fellow great grand-child of Polish King 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.
• Following the sudden death of 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 Landgrave Frederick of Hesse-Kassel, Karl's brother-in-law, two years later.

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