->''As [maternal grandmother] was in early clan marriage (Stone Gang) and shared six husbands with another woman, identity of maternal grandfather open to question. But was often so, and I'm content with the grandpappy she picked.''
-->--'''Manual Garcia O'Kelly-Davis''', ''Literature/TheMoonIsAHarshMistress'' by Creator/RobertAHeinlein

People of strange, exotic cultures are often depicted as being far more open to extended marriages, with three or more participants, than we are. Common in SpeculativeFiction, this emphasizes just how different these people are from us, especially if they are humans like us or HumanoidAliens that still considerably resemble us.

In most of the world today, marriage is limited to two people at a time, but that has not always been the case, there are a few places where it's not the case now, and some authors like to speculate that it may not be true in the future. Some works of HistoricalFiction will use this trope to emphasize the exoticness of foreign or ancient cultures.

Historically, the most common form of extended marriage was one man with multiple wives. The technical term for this is "polygyny",[[note]][[YouKeepUsingThatWord/LessPedantic "Polygamy" is a much more general term while "polygyny" is specific to one man and several wives]][[/note]] and it has appeared in a wide variety of cultures. For this reason, adventure stories set in an exotic corner of the Earth are most likely to feature polygny. To some extent, this can be TruthInTelevision, although ''mere'' polygamy/polygyny is not, of course, an example of this trope.

In works set on other worlds, all sorts of extended marriages can be found, often associated with a FreeLoveFuture. Extended marriage is often shown as an element of both {{utopia}}s and {{dystopia}}s. And when it comes to exotic aliens with {{bizarre alien biology}}, all bets are off. Monogamy may not even be physically ''possible'', let alone desirable.

Subtrope of {{Polyamory}}. The existence of this trope is often a necessity for a MarryThemAll scenario. See the Useful Notes page, UsefulNotes/ForTheLoveOfMany, for a broader discussion of the general topic.

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!! Examples:

[[foldercontrol]]

[[folder: Anime & Manga ]]

* In ''LightNovel/AsobiNiIkuYo'', the Catians have no issues with a male choosing multiple mates. This becomes relevant to the plot when [[spoiler:Kio's house]] is converted into the official [[spoiler:Catian embassy, leaving Kio [[MarryThemAll free to marry]] all three of the girls in love with him]].
* In the canon ''TenchiMuyo'' OVA, Juraian royalty practices just about every kind of old fashioned marriage trope out there: the Emperor has multiple wives, children are encouraged to marry their half-siblings, marrying partners several thousand years your senior (or junior) barely registers the bat of an eye, etc. These practices add some legitimacy to Tenchi's harem situation, leaving open the possibility that he could just MarryThemAll.
* In ''Anime/CodeGeass'', Emperor Charles zi Brittania has OneHundredAndEight wives. This appears to be unique to him, at least of all the canon characters we see.

[[/folder]]

[[folder: Comic Books]]

* A ''[[ComicBook/LoisLane Superman's Girl Friend, Lois Lane]]'' story has Lois fall in love with Titanman, a muscular {{Human Alien|s}}. On their wedding day, Titanman reveals to Lois he comes from a planet that legalized polygamy, and that she will become his ''eighth'' wife. Lois objects to the thought of having to share a husband with seven other women, so Titanman tranquilizes her into proceeding with the wedding. Superman [[OutOfCharacterMoment jealously refuses to save her]], but [[spoiler:she escapes having to marry Titanman by awakening back in the Daily Planet.]]

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[[folder: Fan Works]]

* In the [[{{Rule34}} adult]] "Human In [[WesternAnimation/MyLittlePonyFriendshipIsMagic Equestria]]" work ''Fanfic/{{Xenophilia}}'' and its clean side story ''The Xenophile's Guide to Equestria'', monogamy is considered selfish and somewhat disgraceful, and the typical romantic group starts around four people. While most groups only share flowers, rings, and/or vows rather than getting officially married, even politically important marriages still mean a single person marrying a group. Justified because of a male/female ratio imbalance--male births frequently miscarry.
* ''Fanfic/AMightyDemonSlayerGroomsSomePonies'' has [[Franchise/MyLittlePony Megan]] introducing polygamy (or more correctly, harem-like herds) among the ponies as a necessity due to the male-to-female imbalance. Over the generations, the gender ratio balances out and the ponies slowly switch to monogamy.
* Inverted in ''Fanfic/BaitAndSwitchSTO'', which mentions that the Pe'khdar don't generally practice anything resembling marriage at all. They actually expect sexual relationships to fade, and children are the responsibility of the mother's entire clan.
* Multiple ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' fics have herds being an option, including the ''[[http://www.fimfiction.net/story/29178/the-teacher-the-sorceress-and-the-wonderbolt The Teacher, the Sorceress and the Wonderbolt]]'' series (in which Twilight marries the title characters); ''Fanfic/TheGreatAlicornHunt'', in which Sweetie Belle informs her sister that half the ponies in Equestria were in herds as recently as fifty years before, and it's still perfectly legal, though not as common; and ''Fanfic/SixBridesForTwoSisters'', in which Luna seeks to marry all six Element-bearers at once (and have Twilight also marry Celestia).
* Generally speaking, it sort of goes without saying that the more unrealistic and deliberately wish-fulfillment based fan-fics across a wide variety of fandoms often touch on this trope, many times touching on it as an excuse to detail the HoYay-based scenarios.
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[[folder: Literature ]]
* In ''Literature/{{Dune}}'' Fremen commonly take multiple wives as a way of pinpointing male sterility. Imperial nobles are allowed only one wife but may take bound-concubines whose children by him are considered legitimate (a bit like how things worked in the Ottoman Empire and Qing Dynasty China). Paul is the son of a duke and his beloved concubine (who in a bit of a subversion of the usual course was his ''only'' mate;[[note]]At the time at least; the "[[FanonDiscontinuity prequels]]" hold he had taken another bound-concubine before, the daughter of the deposed and disgraced Earl of Ix.[[/note]] Duke Leto liked to play [[TheVirginQueen Elizabeth I]]'s game and pretend to court various noble women for political advantage), and it causes him no small bit of angst that he has to relegate his Fremen love Chani to a concubine and marry the emperor's daughter in order to legitimize his coup.
* Creator/RobertAHeinlein used this trope a few times, as part of a broader theme of {{Polyamory}} in his works:
** ''Literature/TheMoonIsAHarshMistress'' features extended marriage as a common part of life on the moon, in large part because of a shortage of women. The protagonist, Mannie, is part of what he calls a "line marriage". [[note]]The most common type of marriage is two men with one women, reflecting the relative proportions of the sexes. But Mannie's line marriage has an even balance of sexes - they started with a man and woman who added another husband, then another wife, then another husband, then another wife... Interestingly, the wives make all the decisions (though they let the husbands vote on whether to add another spouse to the marriage, which is ''not'' standard practice in their society) but the family is named after the founding ''husband.''[[/note]]
** ''Literature/{{Friday}}'' starts with the protagonist in a group marriage in New Zealand, although they divorce her after she exposes their racist hypocrisy. She later joins a much healthier group marriage.
* In Donald Kingsbury's ''Literature/CourtshipRite'', the harsh life on the LostColony of Geta has led to extended marriages being quite common. Marriages of up to six people are allowed, and a six-marriage is considered the most perfect, balanced ideal.
* In Creator/CJCherryh's ''Literature/ChanurNovels'', the cat-like Hani form prides, with one dominant male and a group of related females.
* In the ''Literature/EarthsChildren'' series, set in the distant past before the rise of civilization, most matings are one man & one woman, but sometimes a man will mate with two women, or a woman with two men. Whatever works for them.
* ''TheSharingKnife'' has a case where a Lakewalker couple couldn't have children, their families were pressuring them to break up, instead they brought a second husband into the relationship. The husbands are [[BiTheWay married to each other as well.]]
* The novella "The Outcasts of Heaven Belt" by Joan Vinge features a starship crew who are all an intermarried group (although it's usual to have a "special" relationship with just one spouse).
* Gail Dalton's ''Literature/OneRoseTrilogy'' has a society where the size of a marriage ranges from a ''minimum'' of four to a maximum of twelve.
* In Wen Spencer's ''Literature/ABrothersPrice'', a plague has left the world seriously gender-skewed, with 5-10 girls born for every boy. The solution for this is for boys to marry all sisters in a family. The hero, of course, goes on on to marry [[spoiler:all of the princesses of the realm]].
* In the ''Literature/HonorHarrington'' series:
** The planet Grayson (where Honor has dual-citizenship) allows extended marriages (polygynous, due to females greatly outnumbering males on the planet).
** Beowulf runs even more on this, having a wide variety of atypical marital and familial arrangements
* In NnediOkorafor's ''Literature/TheShadowSpeaker'', BadassPrincess Sarauniya Jaa has two husbands.
* In Creator/DavidBrin's ''Literature/{{Uplift}}'' series, uplifted chimpanzees and dolphins are often involved in group marriages, and so do many aliens.
** At the end of ''The Uplift War'', neo-chimp Fiben marries both his love interests, and notes that they're not much help in warding off the attentions of nearly every other female chimp on the planet [[DarwinistDesire who wants his genes]] now that he's a war hero.
** In ''Infinity's Shore'', the neo-dolphin Kaa mentions that his parents were in a "Heinlein-style" line marriage, and his lover Peepoe briefly entertains the notion of being founding matriarch of her own line. [[spoiler: Sadly, it wasn't meant to be.]]
** The species known as the Gubru forms marriages in threes, and doesn't become sexually differentiated until after marriage, when one member of the threesome will become dominant and the sole female, while the other two become male.
* Vonda N. [=McIntyre=]'s ''Starfarer'' series has at least one married triad.
* In Creator/JackMcDevitt's ''Omega'' (part of the ''Literature/PriscillaHutchins'' series), the newly discovered alien race known informally as the Goompahs have a complex system of shared spouses that the researchers studying the race have a hard time figuring out. Conjugal relations are allowed throughout a particular marriage group, but most individuals seem to have one or two preferred spouses within their group.
* In Cherry Wilder's Torin trilogy, beginning with ''The Luck of Brin's Five'', the traditional Torinese family structure is built around a group of five adults, which includes at least one woman and two men in the roles we'd think of as wife and husbands. (Other roles are possible; the five adults can include grandparents as well as parents, for instance.) Biologically, each child has one mother and one father, the same as humans, but all husbands share equally in the raising of each of the family's children, and it's considered impolite to suggest that any of a child's fathers are more or less "really" its father than any other.
* In the ''Franchise/StarWarsExpandedUniverse'', it is revealed that the Cereans (the species to which Ki-Adi-Mundi belongs) have a sex ratio unbelievably lopsided towards females, and that's why they are polygamous. Even Jedi like Ki-Adi are allowed and advised to practice polygamy, since every unmarried or not married enough male is a demographical hazard to the entire race.
* In the ''Literature/{{Marsbound}}'' books, this is a rare but not unusual feature of The Future. In the second book, ''Starbound'', the selected starship crewmembers from Earth are a married triple.
* Several of the future human species in Olaf Stapledon's ''Literature/LastAndFirstMen'' practice different kinds of group marriage. The Last Men have ''96-person'' marriages that can also merge into telepathic group minds.
* In ''Literature/IslandInTheSeaOfTime'' and its sequels, most of the Bronze-Age cultures that the Nantucketers encounter believe in polygamy or polyamory. This leads to some tension between Nantucketer Marian Alston and her Fiernan partner Swindapa, as the latter is bisexual and openly ogles other men or women. Over the course of the books, BigBad William Walker acquires several wives from different cultures as a way of building alliances.
* A number of ''Creator/MCAHogarth's'' universes feature cultures that practice polygamy of some sort.
** In ''Literature/FlightOfTheGodkinGriffin'' some of the many cultures in Shraeven practice a variety of marriages. For instance noblemen are expected to take multiple wives, a few times Angharad thinks of marrying both her lesbian lovers since she's TheEmpire's newly appointed governor of Shraeven, but Ragna says she's not the type who could make it work.
** In the ''Literature/{{Paradox}}'' universe Harat-shar practice polygyny. Chatcaava on the other hand treat their females as slaves and don't so much marry as claim and rape.
** [[Literature/TalesOfTheJokka Jokka]] discourage heterosexual relationships because childbirth has a strong risk of DeathOfPersonality, instead Houses practically treat their females like chattel and assign males to breed them when needed or rent them out to other Houses. However they don't have any problems with homosexual relationships between any number of individuals. [[spoiler: And at the end of ''A Bloom in the North'', it turns out that on the northern continent, where mind-death is practically unknown due to better nutrition, triads with one of each gender are the norm.]]
* [[http://www.amazon.com/Marcus-LaGrone/e/B006MKRCC6 Marcus LaGrone's]] "The Highlands of Afon'' novels feature yet another feline alien example. Highlands Taiks have a four to one female:male ratio so they are polygynous. Traditionally the father is the defender of the family while the First Mother is head of the family's business and the Second Mother mostly raises the kids, Third and Fourth mothers support the First's business. Other races of Taik have a more even gender ratio though, including one that genetically engineered themselves to have very little sexual dimorphism.
* In Francis Carsac's ''Literature/TerreEnFuite'' (''Fleeing Earth''), humans encounter a LostColony in the Etanor (likely Proxima Centauri) system descended from the crew of one of the ship sent out centuries before through the newly-discovered [[SubspaceOrHyperspace hyperspace]] before it was discovered that hyperspace travel is of the BlindJump variety. Due to the fact that the colony (called Tilia) was started by [[AdamAndEvePlot less than two dozen people]] and that various mutations due to exposure to cosmic rays not only skew the ratio of male-to-female births to 1:7 but also result in some males being born completely lacking in initiative, each normal male is required to marry multiple women in order to produce many children. At the same time, the Tilians are a culture of {{Proud Warrior Race Guy}}s, so most able men are soldiers, fighting a war against aliens called the Triss from a neighboring planet. Earthlings, whose technology surpasses that of the Tilians, promise to help them correct the mutation.
* Group marriages in ''[[Literature/TheColorOfDistance Through Alien Eyes]]'' can apparently be of many configurations. There's mention of a triad consisting of two brothers and a woman. A large group marriage has a monogamous dyad within it and Juna marries into this family without entering relations with anyone. These marriages are there for the sense of family and mutual support, and to pool child-rights.
* The ''Franchise/StarTrekNovelVerse'' has it that Andorians practice group marriages of four due to their BizarreAlienSexes. One member of each sex has to take part in a telepathic mating bond called a ''shelthreth'' in order to produce a child.
[[/folder]]

[[folder: Live-Action TV]]
* In ''Series/{{Farscape}}'', Rygel once had many wives, before he was deposed and ended up with the rest of our refugees. Though to be fair, he was the emperor of a multi-system empire.
* ''Franchise/StarTrek'':
** ''Series/StarTrekEnterprise'': Denobulans (both male and female) tend to have three spouses each. Dr. Phlox, the ''Enterprise's'' chief surgeon, thus had a total of 720 people he was directly or indirectly married to.
** ''Series/StarTrekTheNextGeneration'':
*** In one episode the ''Enterprise'' crew has visitors from an alien race where the women are larger in stature than the men and hold all of the business, scientific, and government jobs as well as any occupations requiring physical strength. The smaller men are thought to be better suited for domestic and artistic endeavors. Important women, especially, have multiple husbands, and they all share a marital bed.
*** This trope is the alternate interpretation of a throwaway line from [[Recap/StarTrekTheNextGenerationS4E11DatasDay "Data's Day"]] that Andorian marriages consist of four people. The EU preferred the BizarreAlienSexes interpretation.
** The ''Series/StarTrekDeepSpaceNine'' episode [[Recap/StarTrekDeepSpaceNineS07E13FieldOfFire "Field of Fire"]] has a throwaway mention that a murdered [[RedShirt Gold Shirt]], a Bolian, had a wife and co-husband on Bolias.
* In ''Series/BabylonFive'' Londo Mollari has three wives, all {{Arranged Marriage}}s, whom he hates. It's apparently not uncommon for high status Centauri nobles, and made easier by their [[ExoticEquipment six "appendages".]]
* Clarice on ''Series/{{Caprica}}'' is married to multiple men and women, who are all married to each other. This is implied to be unusual but perfectly legal.
* The Nietzscheans of ''Series/{{Andromeda}}'', a genetically engineered HumanSubspecies who believe in SocialDarwinism, practice polygyny. A male can marry as many females as his displays of genetic fitness attract; alpha males often have ten or more.

[[/folder]]

[[folder: Tabletop Games ]]

* ''TabletopGame/BlueRose'' has "star marriages", where all the participants are considered to be the spouses of all the other participants, even if they are not sexually involved with each other. They are quite common in the islands, uncommon in Aldis and almost unheard of elsewhere.
* ''TabletopGame/DungeonsAndDragons''.
** Dragon magazine #103 article "The Centaur Papers". Centaurs were said to be polygamous. The wealthier a male centaur was, the more wives he had.
** Dragon magazine #116 article "The Ecology of the Minotaur". Minotaurs are polygamous, with each minotaur bull having up to 7 females.

[[/folder]]

[[folder: Video Games]]
* In ''VideoGame/CrusaderKings II'' Muslim rulers can marry as many wives as they have titles, and pagans can take as many concubines as they can capture.
[[/folder]]

[[folder: Web Original ]]

* In ''ChakonaSpace'' Chakats are [[{{Polyamory}} polyamorous]], with a saying that "love doesn't divide, it multiplies". In addition Foxtaurs and Caitians are polygynous due to skewed gender ratios (3-1 and 8-1 females to males respectively). The former two species are Terran, but uncommon enough on earth that [[InterspeciesRomance mates of different species]] have to get used to their idea of monogamy as a foreign concept.
* In the FurryWebcomic ''Webcomic/TwentyFirstCenturyFox'' the giraffes Cecil, Barb, and Beth form a "herd". Their vulpine friends find the idea of wanting to share one male a bit odd.

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