{{otheruses[[Image:Tau Castes.png|thumb|USE=Tau caste systemright|OTHERUSE=Novel by Peter Fehervari300px|OTHERPAGE=[[T'au]] from each of the castes. Left to right: [[Fire Caste (Novel)}}]], [[Earth Caste]], [[Ethereal]] Caste, [[Water Caste]], and [[Air Caste]]{{citeFn|17}}]]The Tau [[T'au]] '''caste system''' is a system of social division that divides all [[Tau]] T'au into five distinct groups.{{Fn|2}}

== Overview ==Each caste is named after an element of nature, symbolising the purpose and temperament of the caste's members. A TauT'au's caste is determined at birth and inherited by one's parents. Inter-breeding is forbidden by the [[Ethereal]]s. For a Tau T'au to choose another caste for himself seems to be impossible, and held contrary to the notions of the [[Greater Good]]. The castes are based upon the racial and political divisions that separated the Tau on their [[homeworld]] of [[T'au (Planet)|T'au]] during the time of the [[Mont'au]]. The Castes were first formally established after the Ethereals brokered peace between warring Tau T'au factions at [[Fio'taun]]. Emphasizing the need for the Greater Good, the Ethereals decreed that the Tau T'au would be formalized into a castecastes, each known by the element that most befitted its role in the new T'au society.{{Fn|6a}} Overstepping ones lot in their Caste and undertaking actions relegated to another is one of the most grievous crimes in Tau society. For instance, an [[Earth Caste]] engineer is usually forbidden from using [[Fire Caste]]-issued weapons in a pitched battle without special permission from the [[Ethereal]]s. Violation of this law commonly results in the accused being sent to a [[Re-education Facility]].{{Fn|615}}

|style="background:#630; color: black" colspan=1 align=center|Trainee rank - — '''SAAL'''{{Fn|1}}|style="background:#630; color: black" colspan=1 align=center|Lowest rank - — '''LA''' |style="background:#630; color: black" colspan=1 align=center|Second lowest rank - — '''UI''' |style="background:#630; color: black" colspan=1 align=center|Middle rank - — '''VRE''' |style="background:#630; color: black" colspan=1 align=center|Second highest rank - — '''EL''' |style="background:#630; color: black" colspan=1 align=center|Highest rank - — '''O'''

|style=background:#c96; align=center|'''[[Fire Caste|Fire - Shas''']]

|align=center|Veteran |align=center|Hero

|style=background:#c96; align=center|'''[[Earth Caste|Earth - Fio''' ]]

|style=background:#c96; align=center|'''[[Water Caste|Water - Por''' ]]

|style=background:#c96; align=center|'''[[Air Caste|Air - Kor''']]

|style=background:#c96; align=center|'''[[Ethereal|Ethereal - Aun''']]

|align=center|Prince

|align=center|King

|align=center|Highest of the Holy

==Shas - Fire Caste==*{{main|Fire Caste}}[[Image:EarthCasteFireCaste.jpg|thumb|right|60px|Earth Fire Caste Symbolsymbol{{Fn|66a}}]]Members of the '''Fire Caste''' are the warriors of the [[T'au Empire]], and as such are most often seen on the field of battle. They have been bred to be the strongest and most aggressive T'au, and weak strains are quickly weeded out. These traits come from the Fire Caste's origin on the plains of [[T'au (Planet)|T'au]], where they were hunters and warriors. [[Fire Warriors]], as soldiers of the Fire Caste are known, spend their entire lifetimes in battle or preparing for it, constantly honing their tactics and working to improve their skills. The strongest of the strong are those T'au from the [[T'au Sept|world]] of [[Vior'la]], who have slightly greater muscle mass because of the stronger gravity of that planet.{{Fn|6a}} The Fire Caste are guided by the [[Code of Fire]] — a doctrine of loyalty, martial arts and merciless war tempered by wisdom.{{Fn|6a}}{{Fn|9a}}

== Fio - Earth Caste ==*{{main|Earth Caste}}[[Image:EarthCaste.jpg|thumb|right|60px|Earth Caste Symbol{{Fn|6a}}]]This caste provides for the manufacturing, agricultural, industrial, artisans, and engineering needs of the Tau T'au Empire. By far the largest caste in sheer numbers, it is they who erect dwellings, provide food, and produce new technology. Members of the Earth Caste are often described as plain and dour, possessing a rather stoic outlook on life in general. They were originally the first Tau T'au to build cities and practice agriculture. The city of [[Fio'taun]] is an example of this, being the first place where the [[Ethereal]]s appeared.{{Fn|66a}}

===Notable Members of the Earth The Water Caste===*also employs criminal investigators known as [[ShoKar'Auntyr]].{{Fn|11}}

*{{main|Air Caste}}[[Image:AirCaste.jpg|thumb|right|60px|Air Caste Symbol{{Fn|66a}}]]The Air Caste is charged with holding the Tau T'au Empire together through the [[Kor'vattra]], the Tau T'au Empire's merchant and war-fleet in addition to operating [[Tau Orbital]]s and [[Fortress Station]]s. Formerly functioning as messengers, these days they are the Tau T'au Navy and are sometimes called the "Invisible Caste", for they rarely if ever set foot upon planets. Living in [[Orbital City|Orbital Cities]], Tau T'au of the Air Caste are the tallest and most slender of all TauT'au, with long, skinny limbs and hollow bones developed due to lives lived mostly in low- and zero-gravity ships and space stations. In the past, before the time of the [[Mont'au]], the Tau T'au that originally became the Air Caste had membranes stretching between their limbs, allowing them to glide on air currents. Tau T'au pilots tend to be superior pilots compared to their [[human ]] counterparts because they have a better depth perception and higher G-tolerance, but lack battle-experience compared to the best Imperial fighter-pilots.{{Fn|6}}  ===Notable Members of the Air Caste===*[[Kor'O'Vanan]]*[[Kor'o Y'eldi]]*[[Valroth]] == Por - Water Caste ==[[Image:WaterCaste.jpg|thumb|right|60px|Water Caste Symbol{{Fn|6}}]]The Water Caste serve the Tau Empire as traders, merchants, public servants, bureaucrats, administrators, diplomats, and ambassadors. They interact with other races when such affairs are not handled by the Fire Caste, and often act as administrators of Tau worlds in the absence of an [[Ethereal]] governor. Like water, Water Caste bureacrats fluidly move between other Castes and alien races incorporated within the Emperor to make sure the Tau Empire flows smoothly. The Water Caste tend to be tall and slender compared to other Tau, and are known for their great linguistic, diplomatic, and negotiation skills. Members of the Water Caste are often the ones who initiate first contact with new species encountered by the Empire, skilfully negotiating their union with the Tau.{{Fn|6}} ===Notable Members of the Water Caste===*[[Golden Ambassador]]*[[Myen O’Res]] == Aun - Ethereal/Celestial Caste ==[[Image:Ethereal Caste.jpg|thumb|right|60px|Ethereal Caste Symbol{{Fn|6}}]]The [[Ethereal]]s serve as "philosopher kings", and guide the other castes, as well as alien member-races of the Tau empire, towards the enlightenment of the ''[[Tau'va]]'', the [[Greater Good]]. They serve as the undisputed rulers of the Tau Empire. Their unique role is a combination of spiritual and political duties, and their declarations shape and steer every action of the Tau Empire. Were an Ethereal to order a Tau to kill himself, he would be met with instant obedience.{{Fn|66a}} Ethereals themselves rule from the [[Ethereal Council]], with the [[Ethereal Supreme]] being the highest ranked of the Caste. They are in turn protected by the [[Ethereal Guard]].

===Notable Members of the Ethereal The Air Caste===*[[Aunalso operates air defences within T'va]]*[[Aun'wei]]*[[Aun'shi]]au territory.{{Fn|13}}

== Gallery ==<gallery heights="250px" widths="300px" modeAun - Ethereal/Celestial Caste="packed" caption="">File:Tau FireWarrior.jpg|Fire Caste warriorFile:Conquestart-earthcastetechnician.png|Earth Caste technician*{{Fnmain|7Ethereal}}File[[Image:Air-caste-pilotsEthereal Caste.jpg|Air thumb|right|60px|Ethereal Caste pilotsSymbol{{Fn|36a}}]]</gallery><gallery heights=The [[Ethereal]]s serve as "300pxphilosopher kings" widths="300px" mode="packed" caption="">File:Air, and guide the other castes, as well as alien member-caste-ground-crewraces of the T'au empire, towards the enlightenment of the ''[[Tau'va]]'', the [[Greater Good]]. They serve as the undisputed rulers of the T'au Empire. Their unique role is a combination of spiritual and political duties, and their declarations shape and steer every action of the Empire. Were an Ethereal to order a T'au to kill himself, he would be met with instant obedience.jpg|Air Caste ground crew{{Fn|46a}}File:Catalogue Tau.jpg|Water Ethereals themselves rule from the [[Ethereal Council]], with the [[Ethereal Supreme]] being the highest ranked of the Caste member{{Fn|2}}File:EtherealMini3.jpg|They are in turn protected by the [[EtherealGuard]].{{Fn|516}}</gallery>

*{{Endn|1}}: [[Fire Warrior (Novel)]], pg. 120{{Cite ThisCME}}, pg. 120 (the canonicity of the information contained in the novel is unclear)

*{{Endn|6}}: [[Codex: Tau Empire (6th Edition)]] :**{{Endn|6a}}: pgs. 8-128–12**{{Endn|6b}}: pg. 36