History Main / RoyalInbreeding

* The Black-Briars of ''VideoGame/TheElderScrollsVSkyrim'' are not royalty, but are still arguably the most powerful family in Skyrim, and this seems to be implied by dialogue from the Eldest son, Hemming. There are certain instances where Hemming will refer to Sibbi and Inguin, his siblings, as his children. Likewise, they are tagged as his children in the game's files, with Maven, the family matriarch, as their grandmother. Yet Sibbi and Inguin will also refer to Maven as their mother. Even worse, Hemming can occasionally be found sleeping in Maven's bed, ''with his mother.'' It's never been confirmed whether or not this was intentional, and Bethesda has something of a reputation for releasing games as ObviousBeta with plenty of DummiedOut content. The above may simply be the result of an earlier concept of the family in which Hemming and Maven were married, that remained partially in the game's files. Though for a character to go from another character's spouse to their offspring is rather unusual on its own...

* In Creator/JamesMichener's ''Hawaii'', the Christian missionaries to Hawaii are appalled by the alii's (Hawaiian nobility) custom of inbreeding. At the time of arrival, the local alii is Malama who's HappilyMarried to her brother Kelolo. While the missionaries ''do'' object to this, it's also "grandfathered in" in a sense because they've already been married for decades. When Malama and Kelolo's children, Keoki and Noelani, are wed ''after'' the arrival of the Christians, Reverend Abner Hale is even ''more'' upset. He has the following conversation with a fellow missionary, John Whipple. Whipple has relaxed his views about a lot of things since arriving in Hawaii and Hale thinks he's GoingNative.

--->'''King:''' But the earl is my uncle, that would make her my... half-sister?\\

* The Black-Briars of ''VideoGame/TheElderScrollsVSkyrim'' are not royalty, but are still arguably the most powerful family in Skyrim, and this seems to be implied by dialogue from the Eldest son, Hemming. There are certain instances where Hemming will refer to Sibbi and Inguin, his siblings, as his children. Likewise, they are tagged as his children in the game's files, with Maven, the family matriarch, as their grandmother. Yet Sibbi and Inguin will also refer to Maven as their mother. Even worse, Hemming can occasionally be found sleeping in Maven's bed, ''with his mother.'' It's never been confirmed whether or not this was intentional, and Bethesda has something of a reputation for releasing games as ObviousBeta with plenty of DummiedOut content. The above may simply be the result of an earlier concept of the family in, in which Hemming and Maven were married, that remained partially in the game's files. Though for a character to go from another character's spouse to their offspring is rather unusual on its own...

This is TruthInTelevision, even with siblings (as in AncientEgypt), primarily as a tool to keep land and other forms of inherited wealth in the same family or to renew alliances.

This is TruthInTelevision, even with siblings (as in AncientEgypt), primarily as a tool to keep land and other forms of inherited wealth in the same family, or to renew alliances.

* This is implied in ''Manga/{{Naruto}}'' with several ninja clans. Sasuke's parents both look like they could have been Uchiha prior to marriage (though an anime filler implies that Mikoto might not be naturally an Uchiha, as she and her husband have to travel to visit her parents), Hinata's mother is shown in the anime and looks like a Hyuga (though the fact her eyes are closed means [[TheUnreveal it's impossible to tell for certain]] if she had the Byakugan or not), and Itachi mentions that he killed his lover during the Uchiha massacre. And given the extreme lengths the Hyuga went through to prevent outsiders from obtaining the Byakugan, it's highly likely they would've favored marriage within the clan. On a less canon and PlayedForLaughs side, ''Manga/RockLeesSpringtimeOfYouth'' exaggerates Neji's BigBrotherInstinct towards Hinata to outright KissingCousins and ''Road to Ninja'' also features an alternate version of Neji that is perverted towards Hinata. Given the large size of both clans, it would be entirely possible for them to have "kept it in the clan" while still marrying fairly distant cousins rather than close relatives.

** Due to a truly TangledFamilyTree, in most continuities Tenchi is (potentially) related to ''all'' of his would-be love interests. Though characterising the exact relationship between Tenchi and Washuu and her family (Ryoko and more distantly, Mihoshi) is tricky. Short version, Washuu is the sister of Tsunami, who is undergoing a long term fusion with Sasami, one of Tenchi's aforementioned great-aunts. So in a way Washuu is Tenchi's great-aunt as well, ''genetically'' she is not since the relation is via [[FusionDance fusion]].

** PlayedStraight -- Lord Helder pursues his cousin, Princess Rellen, once her father is made King of Harbeny and Rellen is made Crown Princess. Helder feels no attraction to her, but as the "second son of a lord's third daughter" he's desperate to marry into a ruling line (even if he'll only be Prince Consort). When King Surno learns of this, he dismisses the idea of his nephew Helder marrying Rellen as "the utmost ridiculousness."
** {{Downplayed}} -- King Surno wishes to have his nephew Lord Helder [[AltarDiplomacy married to]] his niece Lady Poppy. Poppy is the daughter of Surno's brother, while Helder is Surno's nephew by marriage (the son of Surno's wife's sister). In this case Poppy and Helder would have no blood relation (assuming Verato and Surno were not related to the Eldtish royalty that Surno married into).

* The Greek gods have always been their rather inbred selves but the [[ComicBook/WonderWoman2011 New 52]] made ComicBook/WonderWoman the result of inbreeding in the family. She is made the daughter of Hippolyta and Zeus while doing nothing to change Hippolyta's status as Ares' daughter, making Zeus Diana's father and great-grandfather and Ares Diana's grandfather and brother. Traditionally Wondy rather emphatically has no father, and this fan disliked change to her origin was quickly done away with and discredited in ''ComicBook/WonderWomanRebirth'' until James Robinson brought it back to make a storyline centered on one of Diana's brothers from the New 52.

* ''Fanfic/NewTamaran'': Starfire unashamedly admits to coming from eight generations of brother-sister marriage; one could imply that Blackfire’s “defects” are a result from this.

** The current (and last) emperor Artorin's parents had a child each year for as long as the could (he was born in the third year of their marriage, his sister Melissa ten years later) and except for these two, not one sibling survived their first hundred days.

* Discussed and deliberately averted by the House of Winton, the royal family of Manticore in the ''Literature/HonorHarrington'' series. The heir to the throne is required by law to marry a commoner, both to avoid the inbreeding issues that despite the availability of 41st century medical technology still tend to crop up in other aristocratic families and to keep the eventual ruler a bit more grounded.

* Discussed in the third book of ''Literature/TheWarGods'' series, where one man mentions that some of the people in service to Baron Tellian (Whose domain is large enough to be considered a duchy were he any nationality but Sothoii, which has no levels of nobility between 'Baron' and 'Royal') wish that he would marry his only child (Who, being female, cannot inherit directly, instead, passing her claim to her father's lands to her eventual husband) to his nephew Trinial. The man he's talking to says that this would never be permitted as they were first cousins. The first man agrees but points out that people wishing that it ''could'' happen said a lot about Trinial's character (In the end, Leanna renounces her claim on her father's lands to get away from the politics, and Tellian makes Trinial his heir directly).
* In ''Literature/WarriorCats'', the Clans set themselves apart from other cats, believing their social lifestyle superior and other, solitary cats to be 'rogues': untrustworthy, dishonorable and dirty creatures to be driven off their land by force. The Clans display quite a few signs of inbreeding, such as an extremely high rate of stillbirths (generally at least one in every litter larger than three), low overall fertility (litters rarely larger than four, normal would be four or more), and conditions such as 'rex' coats, limb deformities, Klinefelter syndrome, epilepsy, and kinked tails.[[note]]Oddly, however, they've never even heard of polydactyly despite its prevalence in real life.[[/note]] It is never directly stated, but their intolerance of outsiders and small founding population (which was itself derived from a small founding population) would naturally lead to incest and therefore inbreeding. It is telling that the modern [=SkyClan=], who are almost all former pets and ex-rogues, display almost none of these problems. One went deaf, but that's about it.

* In ''Series/DowntonAbbey'', Mary is engaged to her distant cousin Matthew. Since Mary's father, Robert, has no male children, Matthew will inherit his estate. By marrying Matthew, Mary's place at Downton would be secure, and Robert's grandchildren would remain in the line of succession.
* ''Series/TheEmpress'': As in reality, Emperor Franz Joseph is planned to marry his maternal first cousin Helene. He is taken with and marries her younger sister Elisabeth instead.

*** It turns out that, unknowingly, [[spoiler: Jon and Daenerys]] are doing this, as biologically, the latter is the former's aunt, with [[spoiler: Jon's father being confirmed to be Rhaegar Targaryen, who was Daenerys's elder brother. However, Jon puts a stop to it when he finds out and ends up killing Daenerys for unrelated reasons before any offspring can result]].

** It's said that during the most decadent days of the Empire the nobles were so inbred that mutations became commonplace. The Witch Hunters seem to have solved that problem though.

* The Yayoi clan in ''{{VideoGame/Blaz Blue}}'' is one of the oldest members of the Duodecim, the 12 families that formed NOL. They put such an emphasis on preserving their magical abilities that when children who exhibited weaker ars magus aptitude started being born, members resorting to incest and inbreeding in the mad delusion they would get stronger, much to the disgust of the other families. It's specifically noted that Tsubaki isn't the firstborn child of her parents, she's merely the first to ''survive''.

*** Some of the best character traits in the game are hereditary, and become more likely the more common they are in a newborn character's ancestry. The game's mechanics forbid marriage to a sibling, child or parent, but allow grandparent-to-grandchild marriages, among other icky things. Inbreeding excessively will lead to the dreaded "Inbred" trait, which gives a negative 5 to all stats on top of making a character ugly as sin, disgusted by everyone, and unlikely to breed further.

** Both Zoroastrianism band Messalianism came back in ''VideoGame/CrusaderKingsIII'', and not only that it's possible to create your own religion that allows incest. The game also introduces non-incest variants of Zoroastrianism if you wish to avoid this. And the "Blood" dynasty trait improves the chances of a dynasty producing heirs with good genetic traits and reduces the chance of inheriting bad ones (such as the ones leading to Inbred), which is quite helpful for a dynasty engaging in repeated eugenic incest.
* The Black-Briars of ''VideoGame/TheElderScrollsVSkyrim'' are not royalty, but are still arguably the most powerful family in Skyrim, and this seems to be implied by dialogue from the Eldest son, Hemming. There are certain instances where Hemming will refer to Sibbi and Inguin, his siblings, as his children. Likewise, they are tagged as his children in the game's files, with Maven, the family matriarch, as their grandmother. Yet Sibbi and Inguin will also refer to Maven as their mother. Even worse, Hemming can occasionally be found sleeping in Maven's bed, ''with his mother.'' It's never been confirmed whether or not this was intentional, and Bethesda has something of a reputation of releasing games as ObviousBeta with plenty of DummiedOut content. The above may simply be the result of an earlier concept of the family in, in which Hemming and Maven were married, that remained partially in the game's files. Though for a character to go from another character's spouse to their offspring is rather unusual on its own...

* Implied with the von Auslese dynasty of Liberl in the ''[[VideoGame/TheLegendOfHeroesTrailsInTheSky Trails in the Sky]]'' trilogy. At one point in the second game, a family member is compared via a genetic scanner to the FounderOfTheKingdom Celeste D. Auslese (who had lived twelve centuries previous, making the genetic separation roughly 40 generations), and surprised by how high a percentage their genetic match is (73%, suggesting that roughly three quarters of Kloe's ancestors could trace their lineage back to Celeste).

* ''WesternAnimation/{{Tigtone}}'': The king and queen of Propecia are [[{{Twincest}} twins]]. What is even more disturbing is that they are also conjoined twins, who do have sex with each other, somehow. The fact that [[ChocolateBaby their son is a normal looking human who doesn't look too much like]] them turns out to be foreshadowing that he was born from the queen having an affair, somehow. It is later confirmed that the prince is actually the son of the queen and the court wizard. It is unknown how the queen had this affair without the king knowing about it and it's probably for the best.

* The practice of ''[[http://www.iranicaonline.org/articles/marriage-next-of-kin xwedodah,]]'' marriage of close family members to each other, in the noble families of Persia prior to the Arab invasion. Very little information of this practice has survived into the modern day (and it is not practiced by modern-day UsefulNotes/{{Zoroastrian|ism}}s), but it appears to have been a practice grounded partially in religion and partially in culture and was most likely restricted to royals and priests.

* In the Kingdom of Hawaii and its predecessors, intentional incestuous mating was encouraged amongst the ruling classes, despite incest being very rare in other Polynesian cultures. This was because the Hawaiians believed marriages between blood relatives would produce children with very high mana levels, which would translate into semi-divine status that granted mental and physical superiority. Extensive genealogies were kept in order to produce the most inbred (and thus, godly) chiefs possible. The commoners were forbidden to do this out of fears that they would start producing children with chieflike levels of mana.

* In [[JidaiGeki ancient and feudal Japan]], it was common for noble and imperial families to arrange marriages between half- and (more rarely) full- siblings, cousins and even aunts/uncles and nephews/nieces because ThePatriarch of these families tended to [[ReallyGetsAround have boatloads of children from many different women]], and this was a convenient way of tidying up familial loose ends and folding branches of the family back into the main House. In particular, it was rather common for the reigning emperor to be married to a close relative of his ruling shogun. Since the latter tended to also form dynasties, this meant that the two family trees often intertwined. This is, however, {{subverted}} in terms of biology as children of (unrelated) royal concubines are simply declared to be legitimate children of the Emperor and his cousin-wife.

* When the Macedonian Ptolemies took control of Egypt after the split-up of the Alexandrian Empire in the 4th century BC, they revived the Egyptian practice of wedding brothers to sisters to enamor themselves to the Egyptian people, and consequently to keep the Ptolemaic dynasty relatively free of Egyptian riff-raff. They also revived the Egyptian practice of brother-sister spouses [[RulingCouple ruling jointly]], meaning neither party officially had more power than the other. This led to the succession battle that eventually placed the famous [[UsefulNotes/CleopatraVII Cleopatra]] (really Cleopatra VII) as the sole ruler of Egypt despite being a woman.

** To put this into context, Phillip III was Charles II's grandfather through his father and his great grandfather through his mother. Phillip III was related to his own wife, Margaret of Austria, in at least 6 ways (first cousins once removed, 2nd cousins through two different branches, 2nd cousins once removed through two different branches, and 3rd cousins) which made his relation worse than a "typical" first cousin pairing. This came about because Margaret was the result of an uncle/niece pairing while Phillip III was a product of an uncle/niece (also 1st cousins once removed) pairing. Charles II's other great grandfather was Holy Roman Emperor Ferdinand II. Ferdinand II was related to his own wife, Maria Anna of Bavaria, in at least 3 ways (1st cousins, 2nd cousins once removed, and 3rd cousins). Despite Phillip III and Margaret not being true 1st cousins, they were actually more closely related to each other than Ferdinand II was to Maria Anna. Phillip III's daughter, Maria Anna of Spain, and Ferdinand II's son, Holy Roman Emperor Ferdinand III, married each other (adding yet another 1st cousin connection into the mix). Phillip III's son, Phillip IV, then married the product of '''that''' incest, Mariana of Austria to add one last uncle/niece pairing into the mix. To get a good reference, it's scientifically recommended that you not are more closely related to your spouse than 3rd cousins to avoid most complications from incest. An uncle/niece pairing is already 32 times closer to each other than 3rd cousins are.[[note]]Phillip IV and Mariana would be at least ~46.6 times closer to each other than normal 3rd cousins would be. Theoretically, that's still not as bad as the "64 times" greater that would come out of parent/child or sister/brother pairings. That's how bad [[BrotherSisterIncest immediate family pairings are.]][[/note]]

** When the post-Communist Russian government wanted to verify that the human remains found in Siberia were those of the late Tsar Nicholas, they needed a close relative to match the DNA. Prince Philip, Duke of Edinburgh (descended from Victoria through Princess Alice, whose daughter Alix married Tsar Nicholas, and directly related to Nicholas through common descent from Nicholas's maternal grandfather Christian IX of Denmark[[note]]They are first cousins once removed: Nicholas's mother Dagmar/Maria Feodorovna was Christian IX's daughter. Dagmar's brother George I of Greece was Philip's paternal grandfather. Philip's wife the Queen is, interestingly, Nicholas II's second cousin once removed. George I and Dagmar's sister Alexandra is the Queen's great-grandmother (she married Edward VII). Presumably, the geneticists approached Philip and not the Queen because he has fewer generations between himself and the common ancestor Christian IX. (Actually, that had nothing to do with it. The scientists were testing mitochondrial DNA, which is passed down identically through the female line and much easier to compare than autosomal DNA. Philip was matrilineally related to Alix as noted above, while the Queen wasn't. Nicholas II's mtDNA was compared to descendants of his sister Xenia and maternal aunt Alexandra.)[[/note]]) was tactfully approached to give DNA samples. Philip's DNA proved the Romanoff DNA beyond all possible doubt.

** There was the DoubleInLawMarriage between Abdullah I of UsefulNotes/{{Jordan}} to Musbah bint Nasser, and Abdullah's brother Faisal I of UsefulNotes/{{Iraq}} to Musbah's twin sister, Huzaima. Musbah and Huzaima were first cousins to Abdullah and Faisal, all four having the same ancestor in their paternal grandfather, Ali bin Muhammad. Abdullah's son Talal, in turn, married Zein al-Sharaf, Musbah and Huzaima's niece and thus his second cousin. And Talal's son Hussein (father of current King Abdullah II) continued the tradition by marrying Dina bint Abdul-Hamid, his third cousin once removed (she's a great-granddaughter of Awn ar-Rafiq, brother of the aforementioned Ali bin Muhammad), although she only gave birth to a daughter before divorcing Hussein, and his heir Abdullah II was conceived through his English second wife, Antoinette Gardiner.

* Vittorio Emanuele III of Italy was infamously short and of poor health thanks to generations of cousin marriages among his ancestors finally catching up to his dinasty. He was perfectly aware of this, to the point that as the heir to the throne he torpedoed his possible engagement to a German princess precisely because they were related... Resulting in [[ShipperOnDeck literally all royals of Europe joining forces to insure he'd marry Elena of Montenegro]], to whom he wasn't related. His son Umberto II was much taller and of better health.

** To put this into context, Phillip III was Charles II's grandfather through his father and his great grandfather through his mother. Phillip III was related to his own wife, Margaret of Austria, in at least 6 ways (first cousins once removed, 2nd cousins through two different branches, 2nd cousins once removed through two different branches, and 3rd cousins) which made his relation worse than a "typical" first cousin pairing. This came about because Margaret was the result of an uncle/niece pairing while Phillip III was a product of an uncle/niece (also 1st cousins once removed) pairing. Charles II's other great grandfather was Holy Roman Emperor Ferdinand II. Ferdinand II was related to his own wife, Maria Anna of Bavaria, in at least 3 ways (1st cousins, 2nd cousins once removed, and 3rd cousins). Despite Phillip III and Margaret not being true 1st cousins, they were actually more closely related to each other than Ferdinand II was to Maria Anna. Phillip III's daughter, Maria Anna of Spain, and Ferninand II's son, Holy Roman Emperor Ferdinand III, married each other (adding yet another 1st cousin connection into the mix). Phillip III's son, Phillip IV, then married the product of '''that''' incest, Mariana of Austria to add one last uncle/niece pairing into the mix. To get a good reference, it's scientifically recommended that you not are more closely related to your spouse than 3rd cousins to avoid most complications from incest. An uncle/niece pairing is already 32 times closer to each other than 3rd cousins are.[[note]]Phillip IV and Mariana would be at least ~46.6 times closer to each other than normal 3rd cousins would be. Theoretically, that's still not as bad as the "64 times" greater that would come out of parent/child or sister/brother pairings. That's how bad [[BrotherSisterIncest immediate family pairings are.]][[/note]]

** Cersei and Jaime Lannister are twins who secretly have an affair. They have three kids. The good news: the younger two are sweet kids, and seemingly okay! The bad news: The eldest is [[RoyalBrat Joffrey]] [[TheCaligula Baratheon]], who starts a three-way civil war with two secessions. Jaime and Cersei tried to justify their relationship by citing the Targaryen practice, but both felt great pangs of guilt wondering if their sin led to their thoroughly rotten eldest. Also of note is that Cersei's and Jaime's mother and father were [[KissingCousins first cousins]], although [[ValuesDissonance first cousin marriage is unremarkable in Westeros and isn't considered incest.]]

* ''LightNovel/TheIrregularAtMagicHighSchool'' uses this trope as a sudden plot twist in the 16th volume when it becomes clear that [[spoiler: Tatsuya [[BrotherSisterIncest should become the future husband of his own sister]] so that his unique abilities remain forever in the clan. So, as his sister is a perfect {{Designer Bab|ies}}y, their siblings marriage will not be dangerous for their children and eventually give their clan even stronger offspring than if she married another person.]] And although the rest of the magical world as a whole averted it (as mentioned, even a marriage between cousins is considered undesirable due to possible genetic problems), we learn that [[spoiler: Yotsuba]] is not the first clan that started experimenting with incest thanks to new opportunities offered by genetic engineering.

* Website/SCPFoundation: [[http://www.scp-wiki.net/scp-3288 SCP-3288]] is a branch of the Hapsburg family that took this to severe extremes: thanks to Leopold I experimenting with alchemy, the family is able to interbreed with few of the downsides of inbreeding. The deformed ones are sent to underground crypts, but otherwise don't suffer any ill effects such as poor health and infertility: in fact their deformities make them ''stronger''. As time passed those in the underground kept breeding with each other (with [[ParentalIncest parental]] and [[BrotherSisterIncest sibling]] incest being commonplace) until [[spoiler:their blood got so 'pure' and toxic that even children conceived with a non-Hapsburg woman (usually through rape) will come out pure Hapsburg (and by come out I mean ''[[ImAnHumanitarian they eat their way out of their mother]]''). The Hapsburg they captured revealed that this was their entire plan, and they won't stop until the entire earth is populated by Hapsburgs. The worst part? The Foundation's only contained ''some'' crypts. They don't know how many are actually out there.]]

* Implied with the von Auslese dynasty of Liberl in the ''[[VideoGame/TheLegendOfHeroesTrailsInTheSky Trails in the Sky]]'' trilogy. At one point in the second game, a family member is compared via a genetic scanner to the FounderOfTheKingdom Celeste D. Auslese (who had lived twelve centuries previous, making the genetic separation roughly 40 generations), and surprised by how high a percentage their genetic match is.

* Implied with the von Auslese dynasty of Liberl in the ''[[VideoGame/TheLegendOfHeroesTrailsInTheSky Trails in the Sky]]'' trilogy. At one point in the second game, a family member is compared via a genetic scanner to the FounderOfTheKingdom Celeste D. Auslese, and surprised by how high a percentage their genetic match is.

[[caption-width-right:350:"[[Series/GameOfThrones The Targaryens wed brothers and sisters for three hundred years to keep bloodlines pure.]]"\\

* In [[JidaiGeki ancient and feudal Japan]], it was common for noble and imperial families to arrange marriages between cousins and even aunts/uncles and nephews/nieces because ThePatriarch of these families tended to [[ReallyGetsAround have boatloads of children from many different women]], and this was a convenient way of tidying up familial loose ends and folding branches of the family back into the main House. In particular, it was rather common for the reigning emperor to be married to a close relative of his ruling shogun. Since the latter tended to also form dynasties, this meant that the two family trees often intertwined. This is, however, {{subverted}} in terms of biology as children of (unrelated) royal concubines are simply declared to be legitimate children of the Emperor and his cousin-wife.

** The Targaryen dynasty wed [[BrotherSisterIncest brother to sister]] (not as often as you'd think, but likely more often than you want to imagine), [[KissingCousins first cousin to first cousin]] (most common), or even uncle to niece (occasional) for centuries, which is often blamed in-universe for their tendency to produce the odd [[TheCaligula mad king]] (mainly by those very strongly of the Faith and rather biased on the whole issue). It got to the point that Daenerys (the series's most prominent Targaryen) only has ''two'' great-grandparents rather than eight because her parents and grandparents were brothers and sisters. It's suggested that the Targaryens have some sort of strengthened genes because they are, for the most part, physically sound, whereas the extent of such inbreeding would be genetically disastrous if it is practiced in real life (Daenerys is more inbred than the infamous Charles II of Spain). That said, many Targaryen kings did have to contend with higher-than-average rates of infertility and stillbirths, and plumbing the depths of Targaryen history will reveal more than a fair amount of royal children born with extra toes, webbed fingers, and scales… although that might also indicate that their claims to be "blood of the dragon," which such practices were meant to preserve, were NotHyperbole.

* In Creator/JamesMichener's ''Hawaii'', the Christian missionaries to Hawaii are appalled by the alii's (Hawaiian nobility) custom of inbreeding. At the time of arrival, the local alii is Malama who's HappilyMarried to her brother Kelolo. While the missionaries ''do'' object to this, it's also "grandfathered in" in a sense because they've already been married for decades. When Malama and Kelolo's children, Keoki and Noelani, are wed ''after'' the arrival of the Christians, Reverend Abner Hale is even ''more'' upset. He has the following conversation with a fellow missionary, John Whipple, who has relaxed his views about a lot of things since arriving in Hawaii and who Hale thinks is GoingNative.

* Believed to be averted for the pre-1730 [[https://en.wikipedia.org/wiki/Natchez_people Natchez]], and some historians extrapolate backwards from them to argue that earlier Mississippian-culture tribes averted this trope as well. ''If'' the writings of early European colonists are accurate, the Suns (Natchez royalty) and nobles were legally required to marry commoners.

* Effectively {{defied}} in the European royal houses by the late 19th century, as rampaging [[https://en.wikipedia.org/wiki/Haemophilia haemophilia]] among the royal houses and other defects (Victor Emmanuel III, king of UsefulNotes/{{Italy}}, was infamously short and of ill health and conscious of it, and openly blamed it on being the son of two already inbred cousins) led them to carefully arrange marriages to avoid it, culminating in [[BenevolentConspiracy the entire Italian government and every single royal of Europe except the future Victor Emmanuel III joining forces to trick him into marrying Elena of Montenegro due her being completely unrelated to him]] after he refused a possible marriage with a Danish princess for fear his children would be too inbred. Today, haemophilia has been eradicated from the royal families, and Victor Emmanuel III's children were all known in Italy for their perfect health.

** To put this into context, Phillip III was Charles II's grandfather through his father and his great grandfather through his mother. Phillip III was related to his own wife, Margaret of Austria, in at least 6 ways (first cousins once removed, 2nd cousins through two different branches, 2nd cousins once removed through two different branches, and 3rd cousins) which made his relation worse than a "typical" first cousin pairing. This came about because Margaret was the result of an uncle/niece pairing while Phillip III was a product of an uncle/niece (also 1st cousins once removed) pairing. Charles II's other great grandfather was Holy Roman Emperor Ferdinand II. Ferdinand II was related to his own wife, Maria Anna of Bavaria, in at least 3 ways (1st cousins, 2nd cousins once removed, and 3rd cousins). Despite Phillip III and Margaret not being true 1st cousins, they were actually more closely related to each other than Ferdinand II was to Maria Anna. Phillip III's daughter, [[NamesTheSame Maria Anna]] of Spain, and Ferninand II's son, Holy Roman Emperor Ferdinand III, married each other (adding yet another 1st cousin connection into the mix). Phillip III's son, Phillip IV, then married the product of '''that''' incest, Mariana of Austria to add one last uncle/niece pairing into the mix. To get a good reference, it's scientifically recommended that you not are more closely related to your spouse than 3rd cousins to avoid most complications from incest. An uncle/niece pairing is already 32 times closer to each other than 3rd cousins are.[[note]]Phillip IV and Mariana would be at least ~46.6 times closer to each other than normal 3rd cousins would be. Theoretically, that's still not as bad as the "64 times" greater that would come out of parent/child or sister/brother pairings. That's how bad [[BrotherSisterIncest immediate family pairings are.]][[/note]]

* In Creator/JamesAMichener's ''Hawaii'', the Christian missionaries to Hawaii are appalled by the alii (Hawaiian nobility) custom of inbreeding. At the time of arrival, the local alii is Malama who's HappilyMarried to her brother Kelolo. While the missionaries ''do'' object to this, it's also "grandfathered in" in a sense because they've already been married for deacdes. When Malama and Kelolo's children, Keoki and Noelani, are wed ''after'' the arrival of the Christians, Reverend Abner Hale is even ''more'' upset. He has the following conversation with a fellow missionary, John Whipple, who has relaxed his views about a lot of things since arriving in Hawaii and who Hale thinks is GoingNative.

* In James Michener's ''Hawaii'', the Christian missionaries to Hawaii are appalled by the alii (Hawaiian nobility) custom of inbreeding. At the time of arrival, the local alii is Malama who's HappilyMarried to her brother Kelolo. While the missionaries ''do'' object to this, it's also "grandfathered in" in a sense because they've already been married for deacdes. When Malama and Kelolo's children, Keoki and Noelani, are wed ''after'' the arrival of the Christians, Reverend Abner Hale is even ''more'' upset. He has the following conversation with a fellow missionary, John Whipple, who has relaxed his views about a lot of things since arriving in Hawaii and who Hale thinks is GoingNative.

** The Bene Gesserit [[Literature/{{Dune}} intended for Jessica to bear a daughter]] that would be mated to her cousin Feyd-Rautha as part of their SuperBreedingProgram, but she bore a son instead.
** Leto II symbolically married his sister Ghanima, though at that point he was physically unable to have sex so he had [[Literature/ChildrenOfDune Prince Farad'n Corrino (who would be a very distant cousin) sire her children]].
** Over the 3,500 years Leto II controlled the Bene Gesserit breeding program, he [[Literature/GodEmperorOfDune mated several of Duncan Idaho's clones with his sister's descendants]]. While Duncan himself was genetically unrelated to the Atreides family, this obviously became less and less true every time one of his clones fathered a new child.

* ''Manga/{{Berserk}}'': According to the king's brother Count Julius, his son is to marry the king's daughter Charlotte when both came of age. This ends up not happening when [[spoiler:Guts is ordered by Griffith to assassinate Julius and accidentally kills Julius's son in the process when he reflexively attacks on realizing someone's seen him]].

* ''LightNovel/TheIrregularAtMagicHighSchool'' uses this trope as a sudden plot twist in the 16th volume when it becomes clear that the [[spoiler: Tatsuya [[BrotherSisterIncest should become the future husband of his own sister]] so that his unique abilities remain forever in the clan. So, as his sister is perfect a {{Designer Bab|ies}}y, their siblings marriage will not be dangerous for their children and eventually give their clan even stronger offspring than if she married another person.]] And although the rest of the magical world as a whole averted it (as mentioned, even a marriage between cousins is considered undesirable due to possible genetic problems), we learn that [[spoiler: Yotsuba]] is not the first clan that started experimenting with incest thanks to new opportunities offered by genetic engineering.

* ''{{Comicbook/Preacher}}'': It turns out the Holy Grail is indeed the receptacle of Jesus' blood... meaning they're the organisation who've been making the original descendants of Jesus interbreed for nearly 2,000 years to keep his bloodline pure. The results are universally handicapped, deformed (the latest was born with eyes half the size of his head), anything but divine... yet somehow less physically freaky than the family of one-eyed hillbillies Jessie met and befriended.

* In the ''ComicBook/XWingRogueSquadron'', [[RightfulKingReturns Rightfully Returning Princess]] Plourr Illo is surprised to see her second cousin Rial again, and dismayed by his belief that they'll go along with the old ArrangedMarriage set up when they were children. Her bloodline has in-bred and been tampered with to keep it "pure" (including with couples more closely related than just second cousins), which sometimes has disastrous results. Such [[spoiler:[[TheCaligula Plourr's murderously psychotic brother]], who she killed while they were still children in order to stop his own killing spree]].