The Tau '''==Overview==Each caste system''' divides all [[Tau]] into 5 groups known as '''castes'''. The castes are is named after the elements an element of nature, symbolising the purpose and closest to temperament of the particular caste in question's members. OneA T'au's caste is determined at birth and inherited by one's parents. Inter-breeding is forbidden by the Etherals[[Ethereal]]s. To For a 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 T'au factions at [[Fio'taun]]. Emphasizing the need for the Greater Good, the Ethereals decreed that the T'au would be formalized into castes, 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|15}}

|style="background:#4F4F4F 630; color: white" colspan=1 align=center|'''casteCaste\Rank'''|style="background:#4F4F4F 630; color: black" colspan=1 align=center|trainee Trainee rank - — '''SAAL'''^{{Fn|1 }}|style="background:#4F4F4F 630; color: black" colspan=1 align=center|lowest Lowest rank - — '''LA''' |style="background:#4F4F4F 630; color: black" colspan=1 align=center|second Second lowest rank - — '''UI''' |style="background:#4F4F4F 630; color: black" colspan=1 align=center|middle Middle rank - — '''VRE''' |style="background:#4F4F4F 630; color: black" colspan=1 align=center|second Second highest rank - — '''EL''' |style="background:#4F4F4F 630; color: black" colspan=1 align=center|highest Highest rank - — '''O'''

|style=background:#c96; align=center|'''[[Fire Caste|Fire - Shas''']]|align=center|underlingUnderling|align=center|warriorWarrior|align=center|veteran Veteran|align=center|hero Hero|align=center|noble Noble or knightKnight|align=center|commanderCommander

|style=background:#c96; align=center|'''[[Earth Caste|Earth - Fio''' ]]|align=center|apprenticeApprentice|align=center|workerWorker|align=center|seniorSenior|align=center|overseerOverseer|align=center|engineerEngineer|align=center|plannerPlanner

|style=background:#c96; align=center|'''[[Water Caste|Water - Por''' ]]|align=center|assistantAssistant|align=center|bureaucratBureaucrat|align=center|envoyEnvoy|align=center|magisterMagister|align=center|diplomatDiplomat|align=center|ambassadorAmbassador

|style=background:#c96; align=center|'''[[Air Caste|Air - Kor''']]|align=center|delivererDeliverer|align=center|messengerMessenger|align=center|carrierCarrier|align=center|pilotPilot|align=center|captainCaptain|align=center|admiralAdmiral

|style=background:#c96; align=center|'''[[Ethereal|Ethereal or Celestial - Aun''']]|align=center|lordLord|align=center|prince Prince|align=center|prelatePrelate|align=center|king King|align=center|holy onesHoly Ones|align=center|highest of the holyHighest

===Rising through the ranks=Shas - Fire Caste==Provided *{{main|Fire Caste}}[[Image:FireCaste.jpg|thumb|right|60px|Fire Caste symbol{{Fn|6a}}]]Members of the warrior survives 4 years of ''active duty'Fire Caste''', he undergoes are the warriors of the first [[Trial by FireT'au Empire]], which can be anything from mere gladiatorial affairs to trial by constant combatand as such are most often seen on the field of battle. If the Shas'la survives his first Trial by Fire, he is promoted They have been bred to be the rank of Shasstrongest and most aggressive T'uiau, or Veteranand weak strains are quickly weeded out. For every consecutive four years of service, These traits come from the Fire Warrior undergoes another Trial. The higher oneCaste's rank within origin on the Fire Casteplains of [[T'au (Planet)|T'au]], the more likely one is to be a where they were hunters and warriors. [[BattlesuitFire Warriors]] pilot. Upon attaining the rank of '''"O"''', a member as soldiers of the Fire Caste may be allowed to retire from active duty are known, spend their entire lifetimes in battle or preparing for it, constantly honing their tactics and become an advisor working to improve their skills. The strongest of the Tau militarystrong are those T's command structure, au from the [[ShasT'arau Sept|world]] of [[Vior'tolla]], who have slightly greater muscle mass because of the stronger gravity of that planet. Other than death this is {{Fn|6a}} The Fire Caste are guided by the only way to leave the Tau military[[Code of Fire]] — a doctrine of loyalty, martial arts and merciless war tempered by wisdom.{{Fn|6a}}{{Fn|9a}}

*{{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, being . By far the builderslargest caste in sheer numbers, farmersit is they who erect dwellings, scientistsprovide food, engineers, etcand produce new technology. They 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 Ethereals [[Ethereal]]s appeared.{{Fn|6a}} {{Clear}}==Por - Water Caste==*{{main|Water Caste}}[[Image:WaterCaste.jpg|thumb|right|60px|Water Caste Symbol{{Fn|6a}}]]The Water Caste serve the T'au 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 T'au worlds in the absence of an [[Ethereal]] governor. Like water, Water Caste bureaucrats fluidly move between other Castes and alien races incorporated within the Empire to make sure that it flows smoothly. The Water Caste 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 T'au.{{Fn|6a}} The members of the Water Caste have a gift for linguistics that has become more and more developed over time, so they able to learn alien languages with ease and show a remarkable ability to emulate and pick up subtlest of communication features.{{Fn|9a}} The Water Caste also employs criminal investigators known as [[Kar'tyr]].{{Fn|11}}

*{{main|Air Caste}}[[Image:AirCaste.jpg|thumb|right|60px|Air Caste Symbol{{Fn|6a}}]]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 warfleetwar-fleet in addition to operating [[Tau Orbital]]s and [[Fortress Station]]s. Formerly functioning as messengers, these days they are the Tau T'au Navyand are sometimes called the "Invisible Caste", for they rarely if ever set foot upon planets. The Tau Living in [[Orbital City|Orbital Cities]], 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|6a}}

==Por - Water caste==The Water Air Caste serve the Tau Empire as traders, merchants, public servants, diplomats, and ambassadors. They interact with other races when such affairs are not handled by the Fire Caste. The Water Caste tend to be tall and slender compared to other Taualso operates air defences within T'au territory.{{Fn|13}}

*{{main|Ethereal}}[[Image:Ethereal Caste.jpg|thumb|right|60px|Ethereal Caste Symbol{{Fn|6a}}]]The [[Ethereal]]s serve as "philosopher kings", and guide the other castes, as well as alien member-races of the Tau 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.{{Fn|6a}} 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]].{{Fn|16}}

*¹[[Fire Warrior (Novel)]] page 120 (the canonicity of the information contained in the novel is unclear){{Tau}}