Tau

Overview

"Death is a preferable alternative to communism"
-Liberty Prime

The T'au Empire (pronounced "TOW" as in "WOW"), also spelled Tau Empire in older Imperial records, is a rapidly expanding, multispecies xenos stellar empire situated within the Imperium of Man's Ultima Segmentum, near the Eastern Fringes of the Milky Way Galaxy. It lies within the reach of the Astronomican.
The T'au Empire was founded by the T'au caste called the Ethereals, who lead the T'au Empire in the name of and in accordance with a disgusting philosophy they have named the "Greater Good" (Tau'va in the T'au Lexicon). A large and growing number of other intelligent, alien races have foolishly allied themselves with the T'au within the empire. The empire has suffered many raids from the Orks, and also seems to lie in the path of several Tyranid splinter fleets of Hive Fleet Kraken.
The T'au (Imperial binomial classification: Tau tau), also spelled "Tau" in older Imperial records, are a young, humanoid and technologically-advanced intelligent species native to the Eastern Fringes of the Milky Way Galaxy. They are fighting to expand their small, but rapidly growing, interstellar empire and extend a philosophical concept they call the "Greater Good" to all the intelligent species of the galaxy.
The T'au claim to be a peaceful species when possible, asking if others will join their cause voluntarily instead of fighting against them. However, if their peaceful overtures are refused, the T'au may well decide to conquer a planet and add it to their growing stellar empire for the Greater Good, searing the flesh from the bones of anyone who stands against their "benign intentions". This pattern of hypocracy is what truly defines T'au culture. They are a people who claim to have the "moral" high ground in all things, while their crimes as a species are just as vile as any other.
T'au society is divided into a number of castes, each responsible for managing a specific aspect of their civilisation. The T'au's central motivating ideal is that everyone in their empire, regardless of their species or culture of origin, will work for the collective betterment of everyone else, an almost mystical philosophy that is embodied in the Greater Good.
The T'au are the dominant species of the T'au Empire, an interstellar polity which is also composed of several other different intelligent species, including the Kroot of Pech, the insectoid Vespids of the world of Vespid, the nomadic psykers of the Nicassar and many others.
However, there are now several Human septs in the empire derived from conquered Imperial Humans or Humans who voluntarily joined the T'au Empire because they were impressed by the concept of the Greater Good. These people are known as Gue'vesa in the T'au Lexicon and they are considered amongst the most vile of Traitors and Heretics within the Imperium.
The T'au are a relatively young species (it has been only 6,000 Terran years since Imperial Inquisitors first noted that the T'au had only just mastered fire and the wheel), and they have evolved rapidly over the past few standard millennia. Unlike other intelligent, starfaring species, the T'au have made remarkable leaps in technology and now represent a real threat to Imperial domination in their region of the galaxy.

History

The Mont'au and the Coming of the Ethereals

The exact date of the founding of the T'au Empire in the Imperial Calendar is unclear. However the way in which the T'au were united as a species is a well-known tale. What is known is that only 6,000 standard years ago, in the 35th Millennium, an Adeptus Mechanicus Explorator fleet discovered the T'au homeworld of T'au and determined that its population of intelligent xenos were a primitive people at the Stone Age level of development, having only just mastered fire. Since then, the T'au have developed very rapidly into a space-faring species.
Earlier in their history, during a period known as the Mont'au, the T'au were a culture built upon warring tribes. During this time, the T'au's legends tell of the first appearance of the Ethereals at the city of Fio'taun. The fortress city of Fio'taun was under assault by the T'au warriors from the plains. Though negotiation had been attempted, the fierce plains warriors would settle for nothing less than the annihilation of the city of Fio'taun.
For five long T'au years the inhabitants held off the savage assaults with their thick walls and plentiful cannons. However, disease and starvation began to take their toll. As the tide of the siege turned, two mysterious T'au appeared. One made his way into the camp of the plains T'au, exuding a quiet authority that no T'au was able to resist. Soon, the leader of the plains warriors was persuaded to parley with the settled T'au of Fio'taun. Similarly, the other mysterious T'au made his way deep into the fortress. Within a few short hours, the gates stood wide open, and T'au of both sides stood ready to talk.
The Ethereals spoke of the importance of peace and understanding between all T'au. They described a Greater Good that each T'au must strive towards. The besiegers and the besieged quickly agreed with the Ethereals and a truce was reached. Across the world of T'au, Ethereals emerged, each with the same quiet authority and message of harmony and cooperation. With the T'au united, they were able to rapidly develop their civilisation's technology, ultimately attaining spacefaring capabilities.
The T'au Empire soon expanded its borders through a series of so-called "Sphere Expansions." The T'au Empire has gone through five main phases of expansion as of the Era Indomitus in the 41st Millennium. These phases are marked by T'au military campaigns during which new worlds and star systems are colonised, conquered, or sometimes peacefully persuaded to accept the Greater Good through diplomacy and a manifest demonstration of the benefits provided by advanced T'au technology.
Apart from the star systems directly colonised and exploited by the T'au, which are known as "septs," the T'au Empire also includes the worlds and star systems belonging to the species of the Kroot, Vespid, and the Nicassar. It is currently unknown if the Leagues of Votann Prospect called the Demiurg by the T'au are full members of the empire, allies, or mere trading partners. The T'au Empire is composed of over twenty fully-developed septs and around one hundred settled worlds, but the exact number and most of their names are unknown to the Imperium.
A known splinter faction among the T'au are the Farsight Enclaves, founded beyond the Damocles Gulf by the T'au Commander Farsight against the orders of the Ethereals. More recently, some worlds and star systems of the Imperium have been conquered by the forces of the T'au, while a handful have seceded from the Imperium outright and pledged their allegiance to the T'au Empire and the Greater Good.

Damocles Gulf Crusade

The Damocles Gulf Crusade, also called the Damocles Crusade, was the first military conflict fought between the Imperium of Man and the rapidly expanding T'au Empire in the Lithesh Sector of the Ultima Segmentum near the galaxy's Eastern Fringes during the 41st Millennium. The conflict ended in a strategic imperial victory, as the Imperium was forced to conclude its military offensive early to deal with the encroaching Tyranid threat. Meanwhile the T'au sought to begin diplomatic negotiations with the Imperium to buy time to repair their completely devistated military industrial complex.
Before the crusade, members of the T'au Water Caste had established trade agreements with Imperial worlds on the frontier of the T'au Empire, near the Damocles Gulf region of the Ultima Segmentum in the galactic east, and exchanges of goods and technology were common. Alarmed by the threat of alien contamination, the Administratum readied a suitable response. Almost a Terran century later, the Damocles Crusade smashed into T'au space, destroying several outlying settlements and pushing deep into the T'au Empire.
When the Imperial fleet reached the T'au Sept World of Dal'yth Prime, however, the crusade ground to a bloody stalemate as the formidable numbers and high technology of the T'au and their Kroot allies thwarted every attempt to capture the world or its star system. Many solar months of terrible fighting ensued with nothing gained on either side.
By late 742.M41 the crusade's commanders eventually agreed to requests from the T'au Water Caste for peace talks. The negotiations were successful and the Imperial fleet withdrew from T'au space unmolested, their reason partly being due to the impending approach of the Tyranid Hive Fleet Behemoth.

Hive Fleet Gorgon

The T'au Empire was invaded by the Tyranid Hive Fleet Gorgon, a splinter fleet of the much larger Hive Fleet Behemoth, in 899.M41. The Tyranids of Hive Fleet Gorgon were exceptional in their ability to quickly adapt on a biological level to new circumstances of battle, such as evolving immunities to the T'au's energy-based weaponry.
This rapid pace of defensive adaptation may have been unique to the Tyranid breeds of Hive Fleet Gorgon, or it may have been a response to conflict with the T'au, who are also a highly adaptable species; albeit on a technological rather than biological level.
The combined forces of the T'au and the Imperium's Astra Militarum destroyed Hive Fleet Gorgon in 903.M41, though only after both Humanity and the T'au lost several colony worlds to the rapacious Tyranids.

Alliance on Malbede

At some point, the T'au sent an expeditionary force to the Imperial planet Malbede where they came into conflict with the Ultramarines Space Marine Chapter in 936.M41. However, the planet proved to be a cursed Tomb World when the fighting of the T'au and the Ultramarines awakened the sleeping Necrons from their tomb beneath the surface. In an effort to combat this terrible threat to both species, the T'au and the Ultramarines combined their forces to defeat the Necrons. Once the conflict was over, the T'au were allowed to evacuate their forces by the Ultramarines Chapter Master Marneus Calgar who proceeded to destroy Malbrede through the use of an Exterminatus order.

War for Kvarium Alpha

In 966.M41, the T'au fought against the Astartes of the Space Wolves Chapter during the War for Kvarium Alpha. On that Ocean World, the Space Wolves' Drop Pods landed deep in the oceans where their occupants, their power armour altered by Space Wolf Techmarines to operate in undersea environments, made a move to engage their enemy.
On the surface, the battle was fought between the two sides with an equally deadly conflict erupting in the depths of the sea between the Space Wolves and T'au Battlesuits. Thunderhawk gunships armed with torpedoes, prop-bombs and missiles were used to great effect against the T'au's Hammerhead tanks and Manta gunships. Ultimately, the Space Wolves proved to be the victor in the conflict, though hundreds of T'au and Space Wolf corpses floated to the surface of Kvarium Alpha's world sea. With their mission complete, the Space Wolves made the long trek back to land across the sea bed.

Taros Campaign

The Taros Campaign was an Imperial military campaign fought by the 4621st Imperial Guard Army and elements of the Adeptus Astartes to reclaim the Imperial desert Mining World of Taros from the T'au Empire and its Kroot and traitorous human allies of the Taros Planetary Defence Force in 998.M41. The campaign was ultimately unsuccessful for the Imperial forces, who took heavy casualties and losses whilst Taros remained in the possession of the T'au, who renamed it T'ros.

T'au Anatomy and Physiology

The T'au's physiology is closely tied to their society, with the T'au of each caste effectively being a subspecies of the larger T'au race. This was initially a result of adaptation and evolution to suit the different environments each group of the proto-T'au species found themselves in on their homeworld of T'au, although interbreeding between the castes was later forbidden by the Ethereals.
The T'au are humanoid in shape, although they have hoofed feet and four-digit hands (three fingers and one thumb). Their skin is grey-blue (although this can vary in pigmentation between T'au septs and colony worlds), rough in texture, leathery, and exudes almost no moisture. Their faces are flat, wide around the eyes, with an "I"-shaped slit running from the center of the forehead to where a Human's nose would be.
T'au vision is considered slightly superior to that of Humans -- their visual spectrum extends a little more into the ultraviolet and infrared wavelengths. However their pupils do not dilate, giving poorer depth perception and providing slower vision focusing reflexes than Humans, particularly in low light conditions. The olfactory organs of a T'au are inside the mouth.
Physical strength and size varies between the T'au castes with the Fire Caste being the strongest of their kind, roughly the size and slightly weaker than an average baseline Human because the T'au homeworld has gravity slightly weaker than that of Terra.
Only two female T'au have ever been illustrated. The first, Commander Shadowsun, appeared to have a more Human face than male T'au; being smoother and sleeker with larger eyes, a nose-like facial feature and a "Y" shaped facial slit. It is not known, however, whether Shadowsun is representative of all female T'au. The second known T'au female, the subject of an Imperial dissection by the magi of the Adeptus Mechanicus, had the facial characteristics of a male T'au.

Tau Battles

The T'au do not possess psykers and as a result have little knowledge of the Immaterium beyond its existence. This gives them some level of resistance to Warp-based powers affecting the mind, but it offers little, if any, protection against physically-manifested offensive psychic powers. This is because the T'au have virtually no psychic presence in the Warp. To a Daemon or any psykers possessed of the witchsight, they appear as a shifting will-o-the-wisp rather than the burning fire that represents a Human's soul. As such, T'au can never possess or develop psychic powers.
The T'au are largely unaware of the perils of the Immaterium and for this reason have conducted research into the nature of the Warp on Medusa V, however, the conclusion was reached that further research was unfeasible, and that "the Warp is no place for the Greater Good and is best left to those foolhardy races who cannot pull back from that terrible realm."
Ethereal Caste members also have a diamond-shaped bony ridge on their head. It is believed by Imperial scholars that through this organ the Ethereals exert a pheromone-based or latent psychic control over the other T'au castes to keep them focused on the Greater Good, but this is mere speculation, and no evidence of this has yet been found.
Due to their notable absence of psychic ability, the T'au have no equivalent to the Navigators of the Imperium, forcing them to travel at sublight relativistic speeds. Their interstellar vessels therefore take much longer than Imperial vessels to traverse the vast distances between the stars, which is one reason their empire has expanded relatively slowly over the centuries.

Tau Fire Warriors

T'au warriors receive only limited training in the arts of close combat, usually depending on Kroot mercenaries to fight in the horrible melees so common in 41st Millennium battles. However, due to the T'au's superior range of vision in the electromagnetic spectrum and a predilection for patience, the T'au have proven themselves to be extremely efficient sharpshooters with the ranged plasma weapons and railguns they primarily rely upon.
The T'au tend to look upon other intelligent species as backwards or misguided. Before the commencement of hostilities they almost always try to reason with their opponents and establish some kind of agreement that will make the use of military force unnecessary. Noted exceptions to this policy are T'au battles with the Orks, Tyranids and the forces of Chaos, with whom the T'au have little to no diplomatic relations. This is due to the fact that the T'au see no way to reason with them, and do not want them in their empire.

Greater Good

The Greater Good, or "Tau'va," is the central philosophy that unites all T'au. It teaches that every self-aware being is equal and plays an important part in T'au society. It tells its adherents to put away petty squabbles and unnecessary things to unite for the greater good of the rest of their species and of all other intelligent species in the galaxy.
The T'au have no desire to destroy another intelligent species' religion or culture -- though it may not mean that the T'au respect their right to live as they please. However, while many embrace this ideology, and even some Imperial worlds have willingly joined the T'au Empire, other species fiercely resist adhering to the Greater Good to pursue their own freedoms, much to the dismay of the T'au, who see these desires as selfish and unenlightened.
Ultimantly this philosphy is a blanket lie built upon centuries of hypocracy to justify attrocities and unjust conquest of the God Emperor's domain on behalf of the Tau Empire.

T'au Caste System

Castes

The T'au employ a caste-based social system that places the good of the many over the good of the few or the individual. In T'au culture, every person is viewed as an essential part of the whole society, though no individual is ever considered more important than the needs of the rest of society.
Social standing is judged primarily by a being's standing within a caste of the T'au, with the suffix 'la designating the lowest rank in the caste (shas'la: Fire Warrior, fio'la: Earth Worker, por'la: Water Bureaucrat) and the suffix 'o designating the highest (shas'o: Fire Commander, fio'o: Earth Planner, por'o: Water Ambassador). The five castes of the T'au are as follows:

Fire Caste (Shas)

The Fire Caste composes the bulk of the ground military of the T'au Empire, and as such are the T'au most often encountered by the Imperium. They average as tall as or slightly shorter than an average Human, and are generally muscular. This comes from the Fire Caste's origin on the plains of T'au, the T'au homeworld, where they survived as hunters and warriors. T'au from the world of Vior'la tend to have slightly greater muscle mass than is common among their species because of the increased gravity of Vior'la.

Earth Caste (Fio)

The Earth Caste is composed not only of the T'au's labourers and technicians, but also artisans, scientists and engineers. They are usually credited with the significant leaps in technology that the T'au Empire has enjoyed. The members of the Earth Caste form the foundations upon which the T'au Empire is built. The inhabitants of this caste are generally short and stout of build.

Water Caste (Por)

The Water Caste is primarily composed of T'au merchants and diplomats. They are tasked with seeking and maintaining diplomatic relations with the other member species of the T'au Empire, as well as maintaining the ease of communication and cooperation between the other castes. The Water Caste are generally taller and slimmer than other T'au, and favor diplomatic training and social grace over confrontation or combat. They are more capable in communicating in the languages of other intelligent species than most other T'au. From the time when the T'au discovered the existence of the Imperium, there are several accounts where Water Caste ambassadors were dispatched to Imperial worlds, and those worlds accepted the Greater Good without a fight to become new T'au septs.

Air Caste (Kor)

The Air Caste of the T'au function not only as messengers, but also as the bulk of the T'au Protection Fleet and the T'au Merchant Fleet. The T'au of the Air Caste are even taller and more slender than the Water Caste, with long, skinny appendages and hollow bones. These traits are attributed to their lives lived mostly in low to zero-gravity voidships and void stations. This is exacerbated by Air Caste reluctance, if not outright refusal, to land on planets, as their skeletons have atrophied to the point where injury and broken bones are commonplace when they spend time in a gravity well. In the past, during the time of the Mont'au before the unification of the T'au tribes, the Air Caste had membranes stretching between their limbs, which allowed them to glide on air currents. T'au Air Caste pilots are recognised as generally superior to Human pilots due to their better fighter craft, though they lack a normal Imperial pilot's level of combat experience.

Ethereal Caste (Aun)

The Ethereals are the political and religious leaders of the T'au. They resemble the Fire and Water Castes physically, but are marked by a diamond-shaped ridge of raised bone in the centre of their foreheads. Their origins are unknown, and most T'au will never refuse a request made by an Ethereal. They are sometimes also found on the battlefield, but whether as leaders or observers remains to be seen. The leader of the Ethereal Caste is a T'au named Aun'Va, the Ethereal Supreme and Master of the Undying Spirit who chaired the Ethereal High Council and served as the head of state or Aun'o of the T'au Empire.

Ethereal Control

One of the theories surrounding the T'au concerns the Ethereals' method of political control over other T'au, and how the Ethereals initially managed to unite a fractured, nomadic species comprised of multiple and mutually antagonistic sub-species constantly at war into a single people and military force.
The proposed causes of this range from the psychic to the biological, including that the Ethereals' diamond-shaped forehead ridge, an organ unique to that caste's anatomy, produces a set of pheromones that make T'au, and to a lesser extent other intelligent species, open to suggestion.
This concept was introduced after fans complained that the initial T'au codex described the T'au in too much of a positive light, and that they were too "good" for the grim, dark Warhammer 40,000 universe. This also led to the introduction of the Vespid Communion Helms, which have a much clearer Orwellian feel that the Vespid are being directly manipulated by the T'au thanks to the helmets that are supposedly for "communication purposes."