|cellpadding=2 cellspacing=1 style="font-size:85%;font:85%"|'''Major Species:'''

|cellpadding=2 cellspacing=1 style="font-size:85%;font:85%"|[[Tau]], [[Kroot]], [[Vespid]]

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|align=center colspan=2 style="font-size:85%;font:85%"|'''Military forces'''<br>

==History==

The exact date of founding of the Tau empire is unclear, however the reasons behind the foundation are. The Tau had become a culture built upon warring tribes. During this time, the Tau legends tell of the first appearance of Ethereals at [[Fio'taun]]. The fortress city of Fio'taun was under assault by the warriors from the plains. Though negotiation had been attempted, the fierce plains warriors would settle for nothing less than the annhilliation of the city of Fio'taun. For five long years the inhabitants held off the savage assaults with their thick walls and plentiful cannon. However, disease and starvation began to take their toll. As the tide of the siege turned, two mysterious Tau appeared. One made his way into the camp of the plains Tau, exuding a quiet authority that no Tau was able to resist. Soon, the leader of the plains warriors was persuaded to parley with the Tau of Fio'taun. Similarly, the other mysterious Tau made his way deep into the fortress. Within a few short hours, the gates stood wide open, and the Tau stood ready to talk.

The Ethereals spoke of the importance of peace and understanding between all Tau. They described a Greater Good that each Tau must strive towards. The besiegers and the besieged quickly agreed with the Ethereals and a truce was reached. Across the land, Ethereals emerged, each with the same quiet authority and message of harmony and cooperation. With the Tau united, a great civilization began.

The Tau empire soon expanded its border through a series of '''Expansion Phases'''. The Tau empire has gone through 3 phases of expansion already. These phases are a period of several Tau military campaigns during which nearby worlds are colonized, conquered, or sometimes peacefully persuaded to join the [[Greater Good]].

===Hive Fleet Gorgon===

{{main|Gorgon (Hive Fleet)}}

The Tau Empire was invaded by [[Hive Fleet]] [[Gorgon (Hive Fleet)|Gorgon]] in 899.[[M41]]. Gorgon was exceptional for its ability to quickly adapt on a biological level to new circumstances of battle, such as evolving immunities to Tau weaponry. This rapid pace of adaptation may have been unique to Gorgon, or it may have been a response to conflict with the Tau, who are also highly adaptable but on a technological level. Combined forces of the Tau and the [[Imperial Guard]] destroyed Gorgon in 903.M41, albeit after losing several trading partners and colony worlds.⁶

==Society==

Tau society is centred around the concept of the Greater Good, where individual Tau sacrifice personal gain in favour of benefiting the Tau race as a whole. It is from this philosophy that the Tau's all-purpose motto, "For the Greater Good!", is derived. The castes, although different in role and organisation, work together for the benefit of all Tau: the Earth caste provide and produce, the Water caste communicate and distribute, the Air caste connect the worlds of the Tau Empire, and the Fire caste protect. The external image of the Tau is that they are altruistic and idealistic, believing in the unification of all "for the Greater Good".

Kroot society is divided into tribes, known as [[Kindred|Kindreds]]. Each Kindred is an extended family group of Kroot and is led by a Shaper, one Kroot with an intuitive understanding of the DNA absorption process all Kroot possess, and responsible for guiding the evolution of their Kindred. The Shaper, upon identifying a beneficial genetic trait, will instruct his Kindred to hunt and consume that animal, and then control the breeding of the Kindred to ensure that the offspring are born with the selected trait. Often, Kindreds will band together, and the Shapers will form a Council, of which the most influential Kindred's Shaper will be made leader of the group. On rare occasions, a Chief will unite a large number of Kindreds underneath him.

The consumption of flesh is one of the key tenets of Kroot spirituality, as it is believed that the consumption of prey imparts the 'spirit' of the prey to the Kroot, which is then passed on to the Kroot's children. This is the average Kroot's understanding of their rapid evolution, with 'spirit' as a substitute for 'genetic trait'. As a part of this, the Kroot believe that when a warrior dies, his spirit should be kept safe by the Kindred. They will consider it their responsibility to consume the bodies of their dead foes, along with their own fallen and elders.

The Vespid warriors, called ''Stingwings'', form tactical units referred to as ''Strains''. Each Strain is lead by a Strain leader.¹ Because the Vespid language is so complex (presumably because of their complex mouths) and only the Strain Leaders are given the apparatus to translate their language to their Tau allies, Vespid Strains are very close knit and a lot of reliance on Strain Leaders come from both sides.

Stingwing Strains are highly sought after in Tau [[Fire Warrior]] [[Cadre]]s because of their high level of maneuverability. They are often used by Tau commanders alongside [[Battlesuit#Crisis Battlesuit|Crisis Battlesuit]]s or used in a scouting role, backing up [[Tau Pathfinder|Pathfinders]]. In the Tau language they are referred to as "Mal'kor," which comes from "Mal" meaning insect and "kor" meaning air.

==Military ==

Tau ground warfare is carried out almost exclusively by the Fire caste, while the Air caste is responsible for aerial and space combat, and providing transport between systems. Fire caste military forces are known as Hunter Cadres, are similar in size and role to an Imperial Guard company, and are primarily made up of Tau from the same sept. Auxiliary forces are drawn from the alien races within the Tau Empire, and Hunter Cadres can include Kroot warriors, Vespid Stingwings, and Gue'vesa, among other forces.

==Tau Septs==

Each sept has its unique cultural identity wholly integrated within the greater Tau culture. This cultural identity seems to mainly derive from which [[Caste System|Tau caste]] is more numerous and influential in the given sept. Currently there are over twenty fully developed septs. Each sept has its own [[Sept Symbol|sept symbol]].