So you have your fantasy setting. The elves are all ruled by the gracious Queen Bona, the dwarves are all loyal to the mighty King Stormhammer, and the orcish hordes are all under the iron fist of Lord Grimdark. And the humans?
Well, the humans have King James, King Seth, Queen Alex, President Ian, Grand Poobah Elaine and Archmage Bill. And they all hate each other.
Humans, as a species, seem to be uniquely prone to factioning and intra-species conflict. If ever humans arise in a story, there are likely to be multiple kingdoms with poor relations. Multiple nations may exist for other races as well, but they usually like each other fine, unlike the humans, who will constantly try to get the edge on their "rival," even in the face of The Horde.
It also has to do with the writing of the other races. There are a number of reasons on why other races tend to be depicted with only one ruler (including but not limited to):
- The assumption that the fantasy races are tribes of like-minded people. Generally, fantasy tends to treat fictional races as human cultures in funny hats, rather than broader species with their own internal complexities and divisions.
- The convenience of having one ruler for each fantasy race (other than humans in this case). As each race is represented by only one country, "racial problems" (including being Always Chaotic Evil) are automatically "country's problems" as well.
This may become an in-universe problem for humanity, as its internal squabbling, feuds and divisions may prevent it from easily challenging species who fight as one group, pool their resources and cooperate freely, and nonhuman factions will often try to exploit this fact. A common subversion is for humans to be precisely as divided as it's expected to be, but also able to put their survival ahead of their grudges and band together when faced with an external threat.
Another common way for this to be used is when a setting is split between a few major, opposing alliances. In these cases, most races will be wholly within one group or the other, but humans will be evenly represented among them all. Even when a specific in-universe detente isn't present, humanity tends to be portrayed as a morally fractious group as likely to be evil as good, even when everybody else is Always Lawful Good or Always Chaotic Evil.
Please note that this is only for cases where the humans are divided, in stark contrast to other races/species in the setting. If everyone hates each other, and the humans aren't special for doing this, then it's not an example.
- Attack on Titan: Discussed. Pixis quotes to Eren the philosophy that humanity needs a common enemy to unite them in purpose. Eren dismisses it as naive, since humanity is currently at the brink of extinction due to the Titans, but are still as divided as ever.
- Worldwar: War of Equals: Discussed and subverted. Atvar points out that there are plenty of Earth nations and that they may be able to use that as an advantage. However, most Earth nations form alliances with each other once the fleet is spotted in order to present a united front.
- The Negotiations-verse: Alluded to and subverted. Celestia, Luna and Shining Armor (if not most of the ponies) thought the war with the humans would be easy due to humanity's history of conflict, divisions over past grudges and petty grievances against each other. To put it lightly, they were taken by complete surprise and were grossly unprepared for when the humans unanimously put their differences aside to defeat the Equestrians.
- Ender's Game: Earth is united under the Hegemon thanks to the threat of the Formics, but the counter-invasion fleet hasn't even reached the Formic homeworld by the time countries start plotting against one another. Within twenty-four hours of the Formics' extinction, there is a war on Earth. There are references to Formic hive queens fighting against one another in the distant past, but an ancient hero called "the Great Queen, the Mother of All" learned to make peace and cooperate with other queens, those who couldn't or wouldn't cooperate were quickly destroyed by those who could, and by the time of the first book internal Formic warfare is a distant memory.
- Garrett, P.I.: Humans are the only race inclined to prolonged large-scale conventional or magical warfare. Other races have the occasional internal spat, but it's usually either at the level of tribal feuding or else decided by a single battle. Civilized non-humans are more inclined to fight members of other species, or as mercenaries for human factions, than their own kind.
- The Lord of the Rings:
- Men are the only race to fight on both sides of the War of the Ring. The good side has the Men of Dale, Gondor and Rohan, along with Dwarves, Elves, Ents and Hobbits. The evil side has the Men of Dunland, Harad, Khand, Rhûn and Umbar, along with Orcs, Trolls and Worgs. There's also a long-standing rivalry between Rohan and Gondor that slows the building of their alliance.
- This is inverted for the War of the Last Alliance, in which all living things, including beasts and birds, were divided between the forces fighting for Sauron and those fighting for freedom. Men and Dwarves are explicitly identified as being on the side of evil as well as good, and this has interesting implications for the monstrous races as well.
- Spin Control by Chris Moriarty features a human-to-human example that is effectively Earthlings Are Divided. The bulk of human-controlled space is run by the United Nations, but Earth's feuding nation-states present an unfamiliar wrinkle to offworlders trying to negotiate with Earth.
- StarCraft: Discussed in the novelization Liberty's Crusade. Mike Liberty states in the framing narrative that one of the main reasons the terrans can hold their own against the zerg and protoss at the tactical level is because they fought among themselves a lot before First Contact. That's also the reason they can't hold their own at the strategic level: they're terrible at making the large coalitions required.
- The Tripods: Before the Masters conquered the Earth, humans regularly fought with each other as they do today. During the trilogy, humans from different national areas joined together and carried out several attacks to defeat the Masters. Shortly after the victory, the humans from different areas had already started squabbling with each other again, to the dismay of the narrator/protagonist.
- Worldwar: The Race invades earth during World War II. America, the Soviets, and Nazi Germany only work together just enough to keep the Race from conquering the entire planet. And even then, they're constantly at one another's throats. Notably, this is one of the reasons the Race has such a hard time conquering Earth: the Race is fully unified and hasn't faced serious warfare in a long time, while humans are constantly sharpening their war-making abilities against each other. Further, all that warfare causes humans to develop technology much more quickly than the Race, who are at about the same level of technology as they were 800 years ago.
- Andromeda: The Systems Commonwealth fell thanks to the Nietzscheans, a Human Subspecies, rebelling. Once the Commonwealth was shattered, the Nietzscheans fragmented into hundreds of competing prides (the pride that had been running things was all but annihilated in the last battle of the war). Many of the assorted planetary governments during the Long Night are also human. In contrast the Vedrans all vanished, the Perseids retreated to their homeworld, the Than re-established their pre-Commonwealth Hegemony...
- Babylon 5: The story arc starts with a unified human government called the Earth Alliance, which encompasses Earth and every other planet colonized by humans. However, by the end of the arc (after the Earth Civil War), Mars (which had a sizeable separatist movement since before the civil war) and some other colonies are independent entitiesnote . The Minbari also had a civil war, between castes in that case, but their race rather quickly reunified when that was settled. All other alien races were also under unified governments and stayed that way.
- Battlestar Galactica (2003): The twelve colonies of Kobol weren't politically unified until the Cylon rebellion. Amongst the refugee fleet, infighting seems to kill as many as the Cylons.
- Farscape: The show's Human Aliens, who are heavily implied to be Transplanted Humans the Sebaceans, are divided into the highly militaristic Peacekeepers and the more peaceful Breakaway Colonies.
- Dungeons & Dragons: In Eberron, of the twelve nations that formed from the breakup of the old Kingdom of Galifar, five are ruled by humans. Every other base race has one nation (except for the elves, but Aerenal — which was never part of Galifar — is isolationist and distant enough that for most Khorvairan political purposes there is only a single elven nation).
- Warhammer has humans as part of numerous different nations, the majority of which you will probably never see, counting The Empire, Bretonnia, the Chaos Hordes, the eternally-squabbling city-states of Estalia, Tilea and the Border Princes, and distant nations such as Araby, the countless kingdoms of Ind, and Far Cathay. By contrast, all other races are united under a single government or, at least, a single unified culture each.
- Command & Conquer: Tiberium Wars: The GDI and Brotherhood of Nod are still fighting as the alien Scrin invade.
- Endless Legend has three human factions (and one formerly human one) — Vaulters, Roving Clans, Ardent Mages, and Broken Lords — fighting with the unified alien races over control of the Lost Colony of Auriga. The Vaulters are the only ones who remember their origins, and their canonical victory results in them returning to space — where they become another human faction fighting for control of the galaxy in Endless Space.
- Endless Space has three separate human factions; the capitalistic United Empire, the Pilgrims who broke off from the rule of the empire to pursue their own goals, and Horatio, who are all clones of a billionaire named Horatio who decided to create an empire consisting entirely of himself. There's also a fourth human faction, the Sheredyn, but background-wise they are the elite fleet of the United Empire and not a separate entity. The Disharmony Expansion Pack also introduces the Vaulters, descendants of the similarly named human faction in Endless Legend, who specialize in science and defense.
- EverQuest II: When the game first launched, there were only two starting locations: the human cities of Qeynos and Freeport. These cities were the only ones that survived through 500 years of wars, cataclysms that tore up the entire planet, and one of Norrath's moons exploding and raining down debris. All the other races had to abandon their homes for various reasons and flock to those cities. With the continent literally split apart and separated by rough seas, a Cold War scenario developed between all the good races of Qeynos and all the evil races who fled to Freeport, with humans on both sides.
- Halo series appears as this at first glance, with the UNSC still in the process of putting down many colonial insurrections when the multi-species Covenant attacked. However, despite its unified government, the Covenant itself is rife with factionalism even within individual species, to the point where they don't even have a unified military — just individual martial organizations that often wage war against each other on behest of their puppet masters in the Covenant's various Ministries, and eventually collapse into a complicated mess of squabbling factions and breakaway groups.
- StarCraft: While all the three races experience some Civil Warcraft, the Terrans have it worst. Their factions include the Terran Confederacy, the Sons of Korhal which become the Terran Dominion, Raynor's Raiders, and the United Earth Directorate. In contrast, the Zerg are a Hive Mind who only fight one another when the Overmind's power is disrupted and the Protoss have one major division who set aside their differences and reunite by Brood War.
- Stellaris: There are two preset empires of humans that can exist in the same game, the xenophilic and democratic United Nations of Earth and the xenophobic dictatorship of the Commonwealth of Man (descendants of a Lost Colony). Every game mechanic relating to species treats them as one and the same, up to and including xenophobia and genocide. By contrast, all other preset species have a single empire and political outlook each.
- Warcraft has this during Warcraft II. The world is expanded from one kingdom fighting off a horde of orcs in the first game to multiple human kingdoms having to unite against a unified Horde despite hating each other (which leads to some betrayals). Meanwhile, the human Alliance also includes elves and dwarves that have no significant internal conflict. Future games move away from this, with the Horde fracturing, revealing that the orcs were fractured before the Horde, and also revealing major factional conflicts for the other races as well.
- WildStar has Cassians, the proud humans of the Dominion, who revere the mysteriously-vanished Eldan as gods and fervently believe in their divine right to rule and spreading the Empire's goodwill throughout the galaxy, and the Exile humans are the rebel faction that split away from the Dominion after a series of oppressive laws created a caste system that caused much dissent among those who found themselves on the lower end of the hierarchy. Both sides agree that reconciliation is impossible at this point. By contrast, the game's alien species are all either wholly on the Dominion's side or on the Exiles'.
- X has this happen due to Earth's colonies getting cut off from the homeworld. The four nonhuman core factions are all under One World Order, but by X3: Terran Conflict there are four separate human governments: the Argon Federation, the Earth State (better known as the Terrans), the Free State of Solara (otherwise known as Aldrin), and the Hatikvah Free League. Earth's paranoia means that they and the Argon immediately become embroiled in a Space Cold War when Earth is reconnected to the gate system, which turns into a Guilt-Free Extermination War by the next game, Albion Prelude, after the Argon suicide bomb Earth's Torus Aeternal. Come X: Rebirth and the shutdown of the jumpgate network, the three inhabited Lost Colony systems the player is in are lead exclusively by humans; the Plutarch Mining Corporation in Albion, the Argon remnant in Omicron Lyrae (a former regional headquarters for the Argon), and the Republic of Cantera in DeVries (an Earth State colony). The Proud Warrior Race Split Dynasty is represented by the Family Rhonkar remnant who controls a single station in Xenon territory, and the Proud Merchant Race Teladi Union who controls a couple massive space stations in a sparsely developed system.