Not all sapient races are covered in this article, only those whom the community has suggested alternative origins beyond what is explicitly stated in the official lore.
Notes on terminology
- Evolution; Evolution does not necessarily function in Warcraft as it is known to in the real world. In Warcraft, there is such a thing as magical evolution. For example, the kaldorei evolved from the energies of the Well of Eternity, ( and naga and blood elves have both evolved from Highborne. ) ( Dwarves evolved from earthen, ) ( undergoing 100,000 years of evolution. ) ( )
- Devolution; To change or revert into something more beast like, or less intelligent from the original race. For example, naga males have lost intelligence during the many years they've devolved into beasts. ( )
Elf and troll origins
There is some controversy that the separate origin of elves and trolls may be intertwined, but each race has their own story according to their own history. For players, the history of the elves is longer and more unified, since the night elf of today largely resembles that of millennia past, whereas the troll of today represents a more chaotic fragmented part of a larger troll diaspora whose history is filled with more continuous conflict. Trolls share traits with night elves, such as their body form and their ears.
- Main article: Elf
According to their own history, the night elves were the first race to "awaken" in Azeroth, ( when a nocturnal tribe of humanoids called the )Kaldorei ( ) ( ) ( ) ( ) ( ) ( settled near the )Well of Eternity between ten and fourteen thousand years ago (sources differ on the exact timeframe). ( ) ( This tribe venerated the moon goddess Elune even before they discovered the Well of Eternity. ) ( They made their way out of the jungles to its shores and, as they stared into its waters, sensed a great power. Setting in motion a course of events that would change the world forever, they dedicated themselves to its study, hoping that they would discover the moon goddess Elune within its waters. ) ( They built crude homes near the vortex of cosmic energy, ) ( and as the powerful Well of Eternity leaked magic into the community it caused them to evolve, ) ( making them strong, wise, and immortal. ) ( Their skin turned various shades of violet, and they grew taller in stature. ) The tribe re-"adopted" the name Kaldorei, which meant "children of the stars" in their native tongue. ( Their studies of the Well eventually led them to discover arcane magic and, after several ages spent in peace and learning, the Kaldorei grew so in power and wisdom that they outstripped the other humanoid races on Azeroth and created the first great civilization, with the Well of Eternity at its heart. )
Due to their early discovery of magic and the Well of Eternity, they may have thought themselves the first race to "awaken," having judged other races to be slumbering in ignorance, even though the other races had near equivalent awareness and civilization. There is no doubt, however, that the elves are an ancient race with a long history that includes a few schisms and internal conflicts. Nevertheless, except for the divergence of the night elves and high elves in appearance, they remain relatively similar to their ancestors.
The first night elven civilization was relatively small, and they remained mostly isolated around the Well of Eternity in the central region of the super-continent of Kalimdor. As their population grew they eventually encountered the trolls who had spread throughout most of the continent. With their superior strength in magic, they managed to beat back the larger population of trolls, and the two groups settled into an uneasy truce. The conflicts were largely a result of elven exploration, as they created smaller towns and outposts rather than larger cities. The night elven civilization reached its height with the reign of Queen Azshara, but was suddenly and catastrophically shattered by the War of the Ancients and the Great Sundering.
The remaining night elves turned away from the great magic-focused civilization that had brought about their downfall, instead focusing on a smaller, druid-based society. Some of the night elves, mostly former Highborne, disagreed with their race's new direction and left to form their own civilization across the Great Sea. This group would eventually evolve into the high elves and form the nation of Quel'Thalas. The other night elves tended to the lands of northern Kalimdor for ten thousand years, defending them against any who would seek to despoil the land. With the second coming of the Burning Legion during the Third War, the night elves came into contact with the other civilized races for the first time in several millennia, and with the loss of their immortality at the war's conclusion they have slowly spread out into the rest of the world.
- Main article: Troll
The trolls' history is as long as that of the elves' (reaching back at least 16,000 years). Thousands and thousands of years ago, the jungles and forests of Kalimdor were ruled by tribes of trolls, wandering packs of beast-men hunting savage sabercats and kodo beasts and offering up their blood in dark rituals. Petrified remains of troll encampments from these days are occasionally turned up during explorations by the Explorers guild. These trolls had nothing that would qualify as even the smallest of towns. Metalworking was unknown to them, and their weapons were carved from the bones of their fallen prey. Engravings on these weapons show scenes of the hunt as well as fierce duels between trolls, suggesting that they were much like their modern descendants, a society ruled by the strong, the cunning and the bloodthirsty. ( Their internal conflicts have twisted and fractured their recall so that most of the trolls that may relate their history, the )Darkspear tribe of trolls, only know the more recent details of their encounter and alignment with the Horde. They came into early conflict with the elves who both conjured awe and intense hatred. Some say their hatred caused them to re-tell the origins of the elves as being a primordial splinter of the troll lineage, but the possibility of troll descending from elf could also be possible. Appearance-wise, trolls have not changed significantly, but politically and culturally they have broken into many sub-groups.
While the night elves were concentrating on learning the secrets of the Well of Eternity, the trolls were spreading throughout the world from their initial location in the southern part as the Zandalar tribe. Early on they split into two empires, the Gurubashi in the south and the Amani up the eastern and north-central coasts. What kept these two empires from constantly warring with each other was the insidious insectoid empire of Azj'Aqir who they focused on to prevent further expansion. Eventually the might of the two troll empires over thousands of years managed to split and isolate the insectoids to the far north and south areas of the continent, but then before the trolls could attempt to resume any expansion in territories not controlled by elves or insectoids, the coming of the Burning Legion shattered the continent and threw the trolls into disarray.
The calamity that broke the world also shattered the unity of the remaining trolls that struggled to survive. Internal conflicts and civil wars scattered what remained. The Gurubashi empire was undone by civil war among the followers of the blood god Hakkar and their opponents. The Amani empire was destroyed by the ascendant high elves with their newly found human allies and finally the spread of the plague of undeath. Just prior to the Second War, Zul'jin attempted to unite all the trolls under his banner; however his defeat at the hands of the High Elves of Quel'thalas shattered his imperial aspirations.
Trolls still hold many outposts throughout Azeroth, but only the Darkspear have prospered since, due to their place in the ranks of the Horde.
Troll and elf lineage speculation
According to several sources including Dungeons & Dragons Warcraft The Roleplaying Game, Lands of Conflict, Magic & Mayhem, Shadows & Light, World of Warcraft: The Roleplaying Game, and Alliance Player's Guide the ancient feral, nocturnal nomadic tribe were called the Kaldorei, who later discover the Well of Eternity. According to these sources night elves were already called Kaldorei (and perhaps night elves) even before the discovery of the well of eternity. The well of eternity gave them magical abilities and evolved them further from their earlier primitive state.
According to some sources like the Warcraft III manual, night elves were not called night elves or kaldorei until after they discovered the well of eternity. ( The well of eternity changed them drastically: in height, skin color, wisdom, strength, and life span (making them immortal).[ )]Blizzard's history of Azeroth does not clearly state that night elves descended from trolls, but some legends suggest the possibility. Alternatively night elves may be descended from Elune herself as some legends state. Which would explain the exact physical features and appearance that they share according to the official blizzard artistic representations of Elune. Cenarius, dryads, night elves, and keepers of the grove share the same physical features at least from the torso up. In fact dryads and keepers are often described as having the upper body of night elves, ( and night elves are sometimes described as "Cenarius' favored children" due to their connection to dryads and keepers. ) ( It is also possible that primitive race that lived near the well merely changed into Elune's image by the magic they were exposed to. Lands of Conflict discusses yet another primitive race that lived before the sundering, the Azotha (early humans) which could also be candidates for the race that lived near the well. ) ( In the novel )The Last Guardian, Medivh tells Khadgar that the Kaldorei were the first to encamp around the well and cast spells. ( )
It should be said that the a few shared physical 'similarities' is very general and should not be viewed as concrete evidence that trolls are related to night elves. For instance, pointed ears: elves, trolls, dryads, Cenarius, goblins (one could reason pointy ears are a trait among those native to Azeroth). According to Blizzard's representation of Elune (noting it is a Blizzard artist's official representation of what Elune's appearance is, as opposed to just one of the in-game night elf carved representations), the night elves look exactly like her. ( )
According to Blizzard's troll compendium, it's up in the air as to if night elves are related to trolls or not, as there is simply not enough evidence to prove either way.
Within the Halls of Lightning, Halls of Stone, and the raid instance of Ulduar there are several blueprints for different Azerothian races, including Trolls, Tauren, Humans (or perhaps early Vrykul) and Elves. The full significance of this is unclear: perhaps they were created by the Titans, or cultivated upon being discovered as native races on the planet. At the very least, the figures demonstrate that the Titans recognized the Trolls and Night Elves as separate races.
There are several different sub varieties of both species, the trolls' including Ice, Sand, Dark, Forest and Jungle trolls. Elven sub races include Naga, Satyr, Harpies and High Elves. High Elves themselves have several descendant races as well, including Blood Elves, Wretched, and Felblood Elves.
The satyr are the descendants of Kaldorei who allied directly with the Burning Legion during the first invasion. These former elves were taken by the demons and twisted into shapes that more accurately reflected their nature.
Harpies are descended from female elves who betrayed Queen Azshara, Sorceress-Queen of Kalimdor, and were transformed into hideous bird-creatures as punishment, although there is some reference in the War of the Ancients books by Richard A. Knakk that implies that harpies descended from the demi-goddess Aviana.
The high elves are a race descended from the Highborne night elves who left Kalimdor and settled in the Eastern Kingdoms, founding Quel'Thalas. When Quel'Thalas and at least 90% of the high elven race was destroyed by the Scourge, they split into two factions.
Many changed their name to "blood elves" in remembrance of their fallen brethren, and would soon become close allies to the Naga. Others remained as high elves, disgusted by blood elven values. These stayed true to their old allies, the Alliance, and are scattered among various cities where they are a clear minority.
When the Well of Eternity imploded, sundering the world many Highborne were trapped in the blast, however as their bodies were so infused with magic they did not die but were twisted by the powers they had released, influenced through the limited though still quite powerful will of the Old Gods, Azshara and her followers were dragged down beneath the raging sea, cursed – transformed – they took on new shapes and became the hateful serpentine Naga.
The creations of the Titans
When the Titans were shaping Azeroth, they created the Earthen. These beings of magical rock were meant to continue to shape Azeroth after the Titans left. After the Well of Eternity erupted the Earthen sealed themselves off in their cities. Centuries later, some of the Earthen of Uldaman awoke to find that they had changed. Their skin was soft and pink. They decided to leave to the surface, eventually finding the mountain of Khaz Modan which they claimed as their new home. Within Ironforge they made a great altar to their creator Titan Khaz'goroth. There are three known cities where the Titans made the Earthen: Uldum in Tanaris, Ulduar in the Storm Peaks, and Uldaman in the Badlands.
It has been revealed that after discovering the Curse of Flesh, the Titans returned to amend it by creating a second version of the earthen, which would be immune to its effects. This explains why there are still earthen in Azeroth today. There seem to be at least two different types of this second version, as the earthen in Uldaman and in Ulduar appear very different.
Frost and iron dwarves bear much more resemblance to their earthen ancestors than normal dwarves do. Frost dwarves have the same markings on their foreheads that the earthen of Uldaman have, suggesting a link between them. And iron dwarves have a bluish glow underneath their "skin", just like the Ulduar earthen.
Troggs and dwarves
The original earthen were created by Khaz'Goroth with help from Eonar. The troggs, like the dwarves, are a mutation from the original earthen design, referenced by the disks of Norgannon. Although the troggs keep the physical toughness of their earthen heritage, they lose nearly all thought capacity and become dumb, short tempered and violent. The titans sealed these mutations away after realizing their uselessness to their cause.
The dwarves of Ironforge were originally of a single large clan, Ironforge clan, which was made of three clans: The Wildhammer Clan, the Bronzebeard Clan and the Dark Iron Clan, with the Ruling High King Modimus Anvilmar as the supreme leader. However, when the High King died with no heir, the dwarves plunged into a civil war - the War of the Three Hammers. Eventually, the Bronzebeard Clan won and banished the other two clans from Ironforge. The Wildhammers accepted their fate and built the city of Grim Batol in the South Wetlands, eventually re-establishing their friendship with the Bronzebeards. The Dark Iron Clan, however, were less forgiving and retreated to Blackrock Spire to plan their revenge. Lead by the sorcerer-thane 'Emperor' Thaurissan and his wife Modgud, the Dark Iron Clan led a two-pronged attack against Ironforge, the Bronzebeard Clan, Grim Batol and the Wildhammer Clan. The battle at Ironforge was unsuccessful and the battle at Grim Batol had some margin of success but Modgud fell in the battle, so the Dark Iron Clan retreated to Blackrock Spire with Ironforge and Grim Batol following close after them. At Blackrock Spire Thaurissan attempted to summon a powerful fire elemental to smite the other dwarves but instead freed Ragnaros the Firelord. Upon the Firelord's rebirth the area around the mountain exploded in an apocalyptic fire, devastating the surrounding land and making the Searing Gorge and the Burning Steppes. The Firelord took the Dark Iron Clan and made them his. The other dwarves stopped before the explosion and fled, sealing the only entrance into the Searing Gorge from Loch Modan.
- Main article: Gnome
It is not known exactly how the gnomes came into being, but like the dwarves, they may be products of the titans. Some gnomes show evidence of their "...ancestral powers" ( ( )sisters of steel). ( )Sand gnomes may be the link between the Earthen and normal gnomes. Recently it was discovered by (ironically) gnomes of the Valiance Expedtition in Northrend that the gnomish race was created by the Titans as mechagnomes. According to Gearmaster Mechazod the gnomes suffer from the "Curse of Flesh", a condition that eventually befalls all creations of the Titans, just as happened to the Earthen. This may be linked with Ulduar.
Humans and vrykul
The vrykul will apparently tie into the Titan creation myth that will unfold as events of the expansion take place, and in a recent interview with lead game designer Jeffrey Kaplan it was revealed that the vrykul are almost like the progenitors of the human race. They were part of the Titan's early plans for creating the original race that ultimately became humans, but they have turned slightly evil.]] Perhaps much like the stony troggs that evolved from the earthen.
The quest  states that vrykul children born in a certain time after their gods "abandoned" them were "weak and ugly". ordered all those children to be killed, but events observed in the preceding quest  hint that not all parents obeyed this order and instead hid their children, to grow up far away from Northrend. The Arathi named the land of Azeroth as a whole in homage to their ancient ancestors, the Azotha. There is evidence of a connection between titans and azotha, ancient evidence can be found in the Azotha ruins. ( Also, in one of the War of the Ancients books )Rhonin is believed to be a variation of earthen that had grown taller than the rest. ( and categorized by night elven scholars (who apparently never encountered vrykul or azotha) as being biologically similar. )
- Main article: Tol'vir
Having been created as guardians and well-keepers of the titan research facilities, the tol'vir, stone beings, alike the earthen and mechagnomes, wrought for the purpose of preserving the cities of Uldum and Ulduar were nonetheless affected by the curse of flesh as much as their kin. Some of them though retaining their earthly structure, were captured by the nerubians and transformed into the obsidian destroyers, claimed afterward by the Scourge and used in the front lines. Used by the silithid in the War of the Shifting Sands, they proved great menaces even to the dragons. Only few free-willed tol'vir remain and only in Uldum. Those subsiding to the curse of flesh may have lost much of their power, but did not lose their purpose, and did not leave Uldum and its secrets. Two groups of fleshy tol'vir now name themselves the Ramkahen and the Neferset – the latter of which has their stone flesh restored by Deathwing.
As mentioned above under Troll and Elf Lineage Speculation, there are some hints as to the relation of some of Azeroth's native races to the titans in certain Wrath of the Lich King raids: in Vault of Archavon and the Ulduar Instances and Raids, several statues frequently line the halls or otherwise decorate the area. These figures appear as constellation-like forms in the shapes of Humans (or Vrykul), Night Elves, Tauren, and Trolls. Exactly what this recognizance in ancient Titan architecture means for the four races is unknown, but certainly implies that all four were present and existed with the Titans' sanction--if they were not outright created in some fashion by them--before they were done with Azeroth.
Richard A. Knaak's novel The Sundering stated that Ysera, the Dragon Aspect, was Malorne's lover and mother of Cenarius. Later, the author Richard A. Knaak clarified that Elune is Cenarius' biological mother, and Ysera is his adopted mother.
The origin of five centaur tribes(Gelkis, Maraudine, Kolkar, Magram, and Galak) is told by the spirit of Keeper Celebras at Maraudon in Desolace. Keeper Remulos, one of the sons of Cenarius, fathered Celebras and several dryads. Jealous of his brother's offspring, Zaetar mated with an Earth Elemental named Princess Theradras. From that unholy love were born the chaotic, misshapen centaurs.
Another legend passed down by night elves, claims that centaurs are the children of one of Cenarius' first three children. According to this legend, Cenarius first three children were, "the centaur", "the dryad", and "the keeper of the grove"(likely Zaetar). His bastard son, the centaur, turned on him out of jealousy of his siblings beauty, and was forever punished by his father. The centaur left and his children formed tribes of centaur of their own, which may include the race centaur found in the Eastern Kingdoms and the tribe Krenka.
While some contend that Cenarius had only two sons, others argue that is not the case. See: Keepers of the Grove: Parentage, Son of Cenarius, Daughter of Cenarius, Krenka, and Centaur (Eastern Kingdoms).
The Evolution of the Aqir
The aqir were intelligent insectoids that ruled the lands of western Kalimdor during the time of the Amani and Gurubashi empires. They were greatly expansionistic and incredibly evil. They fought against the trolls for thousands of years but were eventually defeated and their empire Azj'Aqir were split into two city-states: Azjol-Nerub and Ahn'Qiraj.
The qiraji are the descendants of the aqir that fled to Ahn'Qiraj. The qiraji retained their insectoid forms, but evolved in many different ways resulting in a caste system in their society. The qiraji waged the War of the Shifting Sands against the night elves for many years before the elves, with the aid of the bronze dragonflight, trapped the qiraji behind the Scarab Wall until it was reopened.
The nerubians are the descendants of the Aqir that fled to Azjol-Nerub. They lost their insectoid forms and became spider-like. The spiderlords, which are described mixture of beetle and spider, and the fact they reproduce through queens, are links between the races. These spider-like humanoids reigned on the continent of Northrend until the War of the Spider, when they were tragically defeated by the Scourge and many were turned into undead crypt fiends.
Some speculate that Nerubians are the avatars of an unseen emperor, similar to how the qiraji are avatars of C'Thun.
One theory is that the silithid and aqir are in fact one and the same, and C'Thun directly created the qiraji from the aqir. But despite evidence to support it, the latter is often dismissed due to an argument of intelligence and its controversy.
Another is that the avatars C'Thun created from the silithid were the aqir, with the qiraji and nerubians later splitting off and evolving differently.
Neither have yet to be confirmed by Blizzard and are both merely speculative histories for the races.
Strong demons — the heroes of their kind — can corrupt individuals, tribes, or even whole species.
While not all the corrupted species were created in this way, the majority were created by demons or the use of demonic magics.
- Night elves during the War of the Ancients were given the choice of becoming satyrs by Sargeras, lord of the Burning Legion. Xavius was the first night elf to accept this power.
- Fel orcs are created by when orcs willfully choose to serve the Legion. Some, however, are tricked into service. The orcs, however, are not transformed, only given a bloodrage unnatural to their race. This happens from the drinking of a Pit Lord's blood, or perhaps any demons blood.
- Felblood elf. Like fel orcs before them — the felblood have been corrupted by the Burning Legion. They are a group of Kael'thas Sunstrider's most loyal followers, who were awarded by Kil'jaeden with the gift of being allowed to engorge themselves on demonic blood.
- The Scourge is a corruption of humans by the Plague of Undeath, created by the Lich King. The Forsaken broke away from the Scourge through the intervention of Sylvanas Windrunner.
- The two-headed ogres were originally the elite guards of Gul'dan. He turned these ogres into ogre-magi using the high elven runes at Caer Darrow by re-forming them into the Altar of Storms. He then used the altars to infuse the two-headed ogres (them being inherently slightly smarter than their one-headed brethren) with demonic energies enabling them to wield magics.
- The Mur'gul are a tribe of Murloc from deep in the Maelstrom. Unlike their cousins, however, they were taken over by the empire of Nazjatar, the Naga. Either corrupted from their slavery, or their proximity to an Old God, they are now no longer the Murlocs they once were.
- Corrupted Treants and Ancients are caused by the corruption in the land, created by the Burning Legion in their invasion. This changed not only the land, but nearly all inhabitants in it, as well.
Eredar physiology has been shaped by demonic influences over the course of the many aeons since Sargeras first encountered their race. When the Dark Titan approached the Eredar, the majority chose to develop their already-substantial magical gifts by joining the Burning Crusade. The demonic eredar, called the man'ari (eredun for "wrong" or "twisted"), have since developed into powerful warlocks and wrathguards.
Only those who followed the Prophet Velen and the naaru refused to join the Burning Legion, escaping from their homeworld Argus in an interdimensional transport made of a single huge diamond (now Osha'gun, in Nagrand). The transport crashed into a planet inhabited by primitive orcs, ogres, and arakkoa. These eredar named themselves the draenei ("exiles") and their new home, Draenor.
After generations of peace, Kil'jaeden and Burning Legion rediscovered the draenei. The Burning Legion used corrupted orcs to all but wipe out the draenei race. While those who survived the attacks on Karabor and Shattrath were in hiding, it was discovered that some of the draenei had been corrupted by their contact with the demonic energies of the fel orcs, causing them to mutate physically and mentally. Unable to feel the touch of the Light, the krokul ("broken") draenei were initially shunned by the unaffected draenei. Some of the Broken continued to devolve — these pitiful beings are known as the Lost Ones, and are now barely sentient.
Draenei player characters are unaffected draenei, who escaped from Draenor with Velen after taking back one wing of Tempest Keep, the Exodar, from Prince Kael'thas and his blood elves.
Evolution of ogres
Supposedly, the Ogre race started as an offspring of the Seven Gronn, the giant Ogre Gods. The early Ogres looked like Ogre Lords, giant, cyclopean creatures with bony, calcified protrusions; as well as being smart and powerful. From these came regular Ogres: more humanoid in shape, two-eyed, smaller, not as intelligent, and generally inferior to Ogre Lords.
As the Ogres lived on the same world as the Orcs, a new race would appear that was the result of a union between the two races, the Mok'Nathal. The Mok'Nathal were powerful warriors who are revered amongst the Orcs, but shunned by the Ogres. The Gronn are angered by any Ogre half-breed, finding them an impurity in their bloodline.
Another branch of the Ogres are the two-headed variety. These were created by the orc warlock Gul'dan. Two-headed ogres were held in high regard by their single-headed brethren, and often held positions of great importance, such as the tribe's Shaman. Also, due to the added intelligence of having two heads, the two-headed ogres have an easier time grasping and controlling magic.
The ancestors of modern goblins were enslaved by the jungle trolls of Kezan and forced to mine kaja'mite ore. Exposure to kaja'mite. Goblin alchemical experimentation later produced the hobgoblins. Currently, there is little information about the gilgoblins, which are presumed to be related to goblins and expected to appear in the cataclysm expansion. Goblins are not known to be related to any other races, however they do bear a strong resemblance to imps and humanoid sprites as well as Trolls.
Origin of the species evolution line
- └ Uncorrupted orcs (Mag'har) — Orc — Fel Orc
- └ Eredar — Draenei — Broken — Lost Ones
- └ Man'ari eredar — Wrathguard
- └ Zandalar Trolls — Other Troll variations —(Alleged: Dark Elves, Night Elves, High elves, Blood elves, Wretched, Naga, Satyrs, Harpies )
- └ Gronn — Ogre Lord — Ogre — Ogre Mage
- ├ Giants
- ├ Vrykul — Azotha — Humans
- ├ Mechagnome — Gnome — Leper Gnome
- └ Earthen — Mountain dwarves, Hill dwarves, Frost dwarves, Dark Iron Dwarves
- │ └ — Troggs └ — Skardyn
- └ Iron Dwarves, Iron Vrykul, Iron giants (Only created by Loken)
- ^ a b c d e APG, 75
- ^ a b A&HC, 73
- ^ DF, 150
- ^ HPG, 242
- ^ a b c WC3Man, 47
- ^ WCRPG, 20
- ^ a b c d e WoWRPG, #
- ^ a b c d e S&L, 128
- ^ a b M&M, 14
- ^ a b c d LoC, 17, 30
- ^ WRPG, 20
- ^ Development of the Kaldorei
- ^ Troll Compenium — The Rise of Troll Civilization
- ^ W3Man, #
- ^ MoM, #
- ^ LG, 149
- ^ GameSpot: World of Warcraft: Wrath of the Lich King Interview 2
- ^ GameSpot: World of Warcraft: Wrath of the Lich King Interview 2
- ^ DS, 21