"The field of battle is an intricate puzzle, one a successful commander must solve before his enemy does. Just as one cannot complete a puzzle without all of its parts, so victory on the ground cannot be won without victory in the air. Indeed, it is with the conquest of the skies that one must often begin."

Commander Puretide on the art of aerial warfare
Kor'vattra T'au Navy Fleet 1

The Kor'vattra departs T'au to expand the borders of the T'au Empire.

The T'au Protection Fleet, called the Kor'vattra in the T'au Lexicon, is responsible for the defence of the T'au Empire and the continued expansion of T'au territory in pursuit of the Greater Good. All T'au vessels are crewed by members of the Air Caste. The T'au also maintain a separate fleet for interstellar commercial activities known as the T'au Merchant Fleet.

Even though the T'au are fairly new to space travel, they still present a powerful force to be reckoned with by the other starfaring species of the Milky Way Galaxy. T'au starships cannot use Warp-Drive technology since they as yet have very little knowledge about the Immaterium and have not developed psychic abilities.

T'au Protection Fleet

The Kor'vattra moves to intercept the foe.

The ZFR Horizon Accelerator Engine, also known informally as the ZFR Drive, is a system of interstellar starship propulsion that was the great invention of the T'au Earth Caste and allowed the T'au Empire to expand rapidly during the Second Sphere Expansion.

An ingenious design, this powerful new drive allowed T'au starships to attain velocities close to the speed of light. It is the primary means of T'au interstellar travel, and is used by all of the vessels of the Kor'vattra.



A T'au Or'es El'leath (Custodian)-class Battleship

The T'au Empire has only expanded into space during the last thousand Terran years. Despite this they have made remarkable progress in developing both civilian and military starships, and have now reached a level where their ships can be compared to Imperial designs. The development of the T'au Protection Fleet (known as the Kor'vattra in the T'au Lexicon) has been given the highest priority by the T'au Empire's ruling Ethereal Caste.

Without the Kor'vattra the manifest destiny of the T'au could never be realised and as a species their existence would be at the mercy of celestial phenomena such as meteors or supernova. Once unified by the Ethereal Caste the T'au made incredible technological progress. By the 39th Millennium they had spread through the T'au System and ringed their homeworld with orbital research and manufacturing facilities. Further expansion required a drive system capable of spanning interstellar distances, but this proved to be a more formidable barrier than expected.

The rise of the T'au can be seen to develop through three distinct phases, periods of intense growth known to the T'au as "Spheres of Expansion." Each of these waves of colonisation is marked by a long building up of resources, after which continual waves of exploratory missions are launched, followed, where needed, by military campaigns to solidify territorial gains. Once a T'au colony transforms itself into a stable settlement, it then serves as a jumping-off point for the next expansion.

By the end of the millennia-long First Sphere Expansion, as it later came to be called, the T'au Empire had unfurled across the heavens and consisted of eight fully-settled star systems known as Septs. Named after its prime or "Sept World," a Sept can include any number of additionally colonised planets or moons, as well as other holdings such as listening posts, sensor fields, shield satellites, orbital cities, and mining operations.

Everything is connected, both by a series of space stations and a massive net of communications and sensor relays strung between major locations. Although it might take many generations to establish itself, each Sept is unique, with its own cultural nuances and varying proportions of the different T'au castes and alien populations.

Several factors combined to end the T'au's first great period of rapid growth. Firstly, despite the terrific population explosion their race had been experiencing, their numbers were being stretched too thin, with need for more of every caste being felt. Fire Caste warriors were in particularly high demand; the wars fought to conquer new planets had proven costly, and ongoing conflicts still raged in outlaying areas.

The second reason the First Sphere Expansion came to a halt was simply due to the distances between systems. After colonising the many dense star clusters near their homeworld of T'au in the Eastern Fringe of the galaxy, the expanses between worlds became greater. At that time, it was already impossible to travel the span of the Empire in a single T'au lifetime using the slow sublight drives available to T'au voidcraft, and crossing the black gulfs that surrounded their star systems would take many, many generations. The T'au clearly needed to innovate new methods of interstellar space travel.

The first problem was solved by the integration of the Kroot race into the T'au Empire following the War in the Place of Union, where the T'au and Kroot first allied to defeat a massive assault by the Orks upon the Kroot of the world of Krath and then went on to free other Kroot enclaves under Greenskin assault. In a short period of time, the Fire Caste armies were swollen by billions of additional Kroot warriors to aid the fight for the Greater Good, albeit in a more mercenary fashion than was considered ideal by the ruling T'au Ethereals.

It was only the Earth Caste which had failed to reach their prescribed goal of developing a new method for more rapid interstellar travel. With engineering centres in every Sept working diligently, the Earth Caste provided innumerable innovations for the T'au military and society, but the invention demanded by the Ethereals -- faster propulsion-technology to drive starships -- eluded them.

At last, the quantum leap came from Fal'shia Sept, where its Earth Caste scientists and engineers finalised development of the ZFR Horizon Accelerator Engine. An ingenious design, this powerful new mechanism allowed T'au starships to attain near-light speed. It was this device that would usher in the next phase of progress, as now T'au vessels could reach new star systems in only a few objective Terran years, while their crews experienced very little subjective passage of time due to the relativistic effects of moving at such high speeds.

T'au Starship Development

The first major class of T'au starships built were the ponderous Gal'leath-class ("Explorer") vessels. These leviathans laid the foundations for the T'au Empire and formed the basis of the Kor’vattra for its first wars with the Orks and the Nicassar. The Niccassar were less advanced than the T'au and after their speedy defeat were one of the first intelligent races absorbed into the Empire as part of the Greater Good.

The Orks posed a more difficult problem. Their ships were faster, better-shielded and more heavily armed than that of the T'au. Against such a dangerous enemy the Gal'leath-class was simply too expensive a resource to risk. Fortunately new, more compact drives led to the introduction of the smaller Il'fannor ("Merchant")-class. To counter the numerous Ork escorts the T'au developed their own Kass'l ("Orca") gunships.

The Kass'l would travel inside a larger vessel equipped with the ZFR Drive over long distances, disengaging when they arrived at their destination. This, combined with the introduction of super-heavy Ion Cannons and Barracuda fighters, helped restore the military balance, but it was the power and efficiency of the T'au shipyards that prevented the Empire from being devastated by Orks and Mankind alike.

The Kor'or'vesh Initiative

Engagements with the Imperial Navy during the Damocles Crusade proved unfavourable to the T'au Fleet. In particular, the heavy losses suffered during the first engagement between the T'au and Mankind in the Hydass System proved that their navy was simply not capable of going toe-to-toe with the older empire.

Heavy losses suffered against an assault by Hive Fleet Behemoth also demonstrated that despite the valour of the Air Caste in every engagement, its vessels were out-gunned and lacked the needed maneuvrability to defeat other spacefaring species' starships. The Kor'vattra needed to develop better vessels and evolve its tactical doctrines.

With the blessing of the Ethereal Caste, T'au High Command ordered a major program of research and development and initiated a massive naval construction program known as the Kor'or'vesh initiative. The initiative would develop new starship designs for military use, built with the newest T'au technology and constructed around tactical paradigms informed by the costly losses already taken.

The program was given the highest priority, applied the best Earth Caste engineers to the project and spared no expense. The result were several new classes of T'au warships, beginning with the Il'Porrui-class Cruiser which served as a test bed for many of these new design philosophies, and continuing to include the Kir'shasvre Escort, and the mighty Or'es El'leath-class Battleship and its Kir'la-class gunships.

While individual voidcraft from this program were encountered by Imperial forces prior to the Taros Campaign, that conflict was the first time multiple examples of this generation of T'au starships would see battle against the vessels of the Imperium.

In the wake of the success of the Kor'or'vesh initiative, the older vessels of the T'au Protection Fleet were largely reassigned to what became the heavily-armed T'au Merchant Fleet.

T'au Air Support


A chart outlining the military organisation of the T'au Air Caste in the Kor'vattra

T'au battle plans are works of holistic genius, carefully orchestrated manoeuvres that encompass great swathes of any engagement area. Central to many of these strategies is the establishment of total air superiority. Achieving this goal falls to the brave and selfless pilots of the Air Caste.

Teams of Air Caste combat craft sweep through the skies above almost every battlefield the Fire Caste fight upon. Fighter and bomber teams are fully integrated into the combat strategies of the T'au military, coordinated centrally by Coalition-level command elements and working in perfect concert with the ground forces of the Fire Caste. Their efforts ensure that ground-based cadres can manoeuvre freely, pursuing their own objectives without fear of attack from on high.

Nearly all T'au campaigns begin with a massive Air Caste combat deployment. Each team of fighters or bombers is tasked with achieving specific objectives and provided with ample support to achieve their goals in optimal time. Teams of Razorshark strike fighters switch between high altitude dogfights and ground attack runs, fearlessly scouring the skies of monstrous beasts or obliterating the war engines of the enemy.

While the Razorshark Teams eliminate priority threats, whole contingents of Sun Shark bombers plunge low to perform daring bombing runs against key enemy installations. Airfields, generators, flak batteries and command assets are pounded into submission by energised ordnance to pave the way for full-fledged ground assault by the Fire Caste.

Air caste pilot

A T'au Air Caste Pilot

Air Caste pilots display incredible selflessness, braving unbelievable odds to destroy their targets. They will gladly scream between the questing, building-sized tendrils of a Tyranid Hive Ship or dare the drumming fire of Space Marine Hunter squadrons, stoically accepting their casualties as sacrifices to the Greater Good.

Still, the T'au do not believe in senseless martyrdom; their air groups never commit without a coherent plan and clear target, and they quickly pull out if it becomes apparent that no amount of determination and technology is going to win the day.

Such judgments are left up to the pilots themselves, T'au Commanders relying upon the experience and wisdom of their flight crews in the field. Such trust is well placed. The pilots of the Air Caste are born into their role, biologically adapted to flight thanks to their willowy frames and hollow bones.

Coupled with bodies that can absorb tremendous g-forces is the Air Caste pilots' exceptional training. These skyborne warriors have learned to fly from their earliest days, their entire lives devoted to the absolute mastery of the pilot's art. Most T'au team leaders and fighter aces have more experience than a whole squadron of other species' pilots, all of which they turn to the pursuit of victory for the Tau'va.

T'au Naval Weapons and Systems


T'au turrets are extremely sophisticated defensive starship defensive systems, combining a range of weapon types with overlapping fire zones.

Ion Cannons

Ion Cannon shots vaporise the object struck, magnifying the energy discharge. Armour is of no value against them. They function the same as Imperial Navy starship Lances in all respects.

Railgun Batteries

Railguns of the size mounted on warships require massive amounts of energy to fire despite T'au superconductors. Because of this, power is routed to a single barrel at a time. The sequence is timed to ensure the first barrel is reloaded before it is charged again. Railguns function as standard weapons batteries.

Gravitic Launcher

Gravitic launchers are massive railguns where mass drivers trigger the initial acceleration before the starship's gravitic field is pulsed to squeeze the missiles toward the enemy at enormous speed. The missiles are drone-controlled and exceptionally dangerous.

Gravitic Hook

Gravitic Hooks are large, suspensory arms which create a gravitic sheath in which a small vessel can be transported by a larger one.


T'au shields are formed by shaping the gravitic field to repel incoming fire. They function as normal Void shields in every respect.


The deflector is a specialised type of void shield generally mounted on the prow of the latest T'au starships. It turns the gravitic sheath around the vessel into a dense wedge, which is far more effective against incoming fire. If fired at from the front the deflector augments the passive armour of the T'au vessel. Deflectors are always mounted on the prow and will be disabled if the ship suffers damage to its prow.

Tracking Systems

T'au Skether'Qan-class starships boast highly advanced data storage and processing facilities to cope with the vast amounts of information they carry. When linked to ship sensors though this processing power can be used to provide a direct feed to the ships turrets. In fleet actions Skether'Qan-class starships can route this data to other nearby T'au vessels.


Gal'Leath (Explorer)-class Starship

The Gal'leath-class starship was the cornerstone of the early T'au Protection Fleet. Its massive Ether Drive allowed it to move through Warpspace at a pace 5 times slower than its Imperial counterparts, but this speed was fast enough to facilitate the expansion of the T'au Empire in its fledgling steps outside of its home star system.

The Gal'Leath boasted a massive cargo capacity, extensive scientific research facilities and the ability to serve as a mobile dock for semi-independent starships. Its cargo bays were also large enough to carry modular orbital units, waystations and even (more recently) message boats. It was the galleon of the T'au Empire and for nearly a hundred tau'cyr it was the only class of starship continually in production. During this time it moved from Mark I to Mark XXIII, benefiting from a succession of improvements and special adaptations.

Conflict with the Orks was the class' death knell. It was not a specialist warship and its weaponry was incapable of keeping Terror Ships and Kill Kroozers at a distance. Work on the Il'Fannor-class was accelerated. When it was complete, production of the Gal'Leath-class dropped by 85%. There are, however, still a number in service.

The most recently completed member of the Gal'Leath-class was the Dal'yth Gal'Leath Kessan, the first of the Mark XXIV designs, and the T'au flagship in an expedition launched by the former Ethereal Supreme Aun'shi to discover more about the breakaway Farsight Enclaves. It is unknown whether any further plans exist for continued support of this design.

Or'es El'leath (Custodian)-class Carrier

The T'au Protection Fleet's Or'es El'leath (Custodian)-class carrier is the largest of the starships built under the T'au Empire's Kor'Or'Vesh initiative to expand their military forces. Though it lacks the durability of other races' Battleships, the Or'es El'leath-class is armed to the teeth with every weapon in the T'au arsenal: a staggering array of Railgun batteries, Ion Cannons, and Gravitic Launchers; launch bays for Mantas and Barracudas; and three Gravitic Hooks for carrying Kir'la escorts.

The Or'es El'leath's first major combat action came during the Taros Campaign, when the Or'es El'leath-class carrier A'rho led a T'au fleet against the Imperial forces seeking to retake that system from the T'au Empire. The A'rho acted as a decoy, drawing off several Imperial ships as two Lar'shivre-class cruisers wreaked havok on Imperial supply convoys.


Il'Fannor (Merchant)-class Starship

The Il'Fannor-class Starship was originally developed to be the new workhorse of the T'au Empire. Its reactors were a fraction the size of the much larger Gal'Leath-class' power plant but were capable of reaching a third of the average Warp speed of an Imperial starship, making them significantly faster. This was deemed essential to bind together the emergent T'au Empire.

Conflict with the Orks caused significant revision of the design with field modifications that allowed virtually all of the cargo space to be converted to weapons systems if needed. The continued requirements of the fleet ensured that the Il'Fannor-class remained predominantly a warship until the Lar'Shi-class was laid down.

Lar'Shi (Hero)-class Starship

The pinnacle of T'au technology, the Lar'Shi-class Starship was the product of the T'au's first experience with the Imperial Navy during the Damocles Gulf Crusade. The T'au were determined that they should have a starship that could match the Imperial Lunar-class Cruiser.

As soon became evident, the T'au designers failed at this task but they did succeed in producing a credible ship of the line in the Lar'shi-class.

Lar'shi'vre (Protector)-class Cruiser

The T'au Protection Fleet's Lar'shi'vre (Protector)-class Cruiser is the T'au Empire's primary warship, purpose-built for engaging and destroying enemy starships. Two Lar'shi'vre cruisers participated in the Taros Campaign, wreaking havok upon Imperial shipping as the Or'es El'leath-class carrier A'rho drew off part of the Imperial fleet.

While lacking the armoured bulk and potent, layered defences of its Imperial counterparts, the Lar'shi'vre-class' firepower allows it to go head-to-head with them nonetheless, unleashing terrible barrages of Railgun batteries, Ion Cannons, and Gravitic-launched missiles alongside its squadrons of Barracudas and Mantas.

Il'porrui (Emissary)-class Starship

The T'au Protection Fleet's Il'porrui (Emissary)-class starship is designed for the transport of T'au dignitaries like Ethereals, Fire Caste commanders, and Water Caste diplomats, and not as a true warship.

However, it is armed well enough to protect itself, with gravitic launchers, Railgun batteries, and a pair of launch bays. It is further protected by a deflector that enhances the effectiveness of its front armour. Il'porrui-class starships are becoming increasingly common within the T'au Empire, roving far and wide on diplomatic missions and as merchant vessels.


Kir'Qath (Defender)-class Starship

Just as the Lar'shi is the T'au response to the Imperial Lunar-class Cruiser, the Kir'Qath is their answer to the Imperial Sword-class Frigate. The Kir'Qath is the only true escort in the T'au Protection Fleet and is used in squadron formations to provide close support for the larger vessels.

Its main weakness is the lengthy recharge time for its Phased Warp-Drives. It can make up to half a dozen Warp dives in succession but will then be unable to do any more for at least a rot'aa. This means it is not suitable for scouting as it either travels slowly across interstellar space or risks being unable to retreat when it arrives. This can make it a liability in rapid fleet maneuvers. Consequently, Kir'Qath-class squadrons are spread through T'au space where heavier units can call upon them for support if required.

Skether'Qan (Messenger)-class Starship

The Skether'Qan is the smallest self-sufficient T'au Protection Fleet vessel. It mostly comprises a drive and a cargo hold but it is occasionally used as a fleet scout because it is quite maneuverable and has unmatched data-handling and communications facilities.

These systems were soon adapted for combat applications. The Skether'Qan 's weaponry is purely intended to deter pursuit, so in fleet actions it tends to stay close to a capital ship, helping against attack craft in return for protection against true warships.

Kass'l (Orca)-class Gunship

The Kass'l (Orca)-class Gunship was designed to provide the T'au fleet with an Escort starship. Unable to build a drive light enough to produce a normal Escort, the Kass'l is transported within a capital ship's gravitic sheath. Once unleashed, however, it is a powerful gunship able to contend with any Imperial or Ork escort vessel of similar size.

Kir'la (Warden)-class Carrier Escort

The Kir'la (Warden)-class Escort is a small T'au spacecraft that, lacking a Gravitic drive, must be carried into battle via Gravitic Hooks. It commonly accompanies the T'au Protection Fleet's Or'es El'leath Carrier into battle, as the larger starship contains three Gravitic Hooks purpose-built for carrying Kir'las. Three Kir'la-class ships fought alongside their mothership, the A'rho, during the Taros Campaign.

Kir'shasvre (Castellan)-class Heavy Escort

The Kir'shasvre (Castellan)-class Heavy Escort is a T'au gunship designed during the T'au Empire's Kor'Or'Vesh initiative. It is armed with a Gravitic Launcher and relatively heavy Railgun battery, and is roughly analogous to the Imperium's Sword- and Firestorm-class frigates. Twenty Kir'shasvres accompanied the T'au fleet during the Taros Campaign.


Orca Dropship

The Orca Dropship is a dedicated transport vehicle, designed to ferry troops and supplies between orbiting starships and a planet's surface. Despite sharing a codename with the Kass'l-class Gunship, the Orca Dropship is a pure-bred troop transport designed for use in relatively secure areas, and as such carries only minimal armaments.

Manta Dropship

The T'au Manta Super Heavy Lander is a Missile Destroyer that serves as the T'au equivalent of an Imperial Titan and specialises in supporting ground assaults. It is the largest dropship of its kind, carrying staggering numbers of Fire Caste warriors into battle, supported by dozens of Gun Drones as well as XV8 Crisis Battlesuits.

The Manta consists of two decks, an upper deck where Fire Warriors sit as well as an overseeing member of the Ethereal Caste, and a lower deck, where up to four Devilfish or two Devilfish and two Hammerheads can sit. In addition, up to eight fully armed XV8 Crisis Battlesuits can sit in the lower deck, with half a dozen gun drones up top. The Manta is piloted by at least four Air Caste pilots.

Orbitals (Space Stations)

The T'au have made extensive use of the space stations called orbitals since their earliest forays in space. The Air Caste had always been at the forefront of the conquest of the upper atmosphere for the T'au and provided enthusiastic crews for the first orbitals.

Many orbitals exist purely to provide homes for the Air Caste. Others are used for manufacturing and interstellar trade. Normally, individual orbitals are assembled into arrays of up to five individual orbitals which are all linked together.


Orbital waystations are distributed through the T'au Empire. These mark the main routes between T'au Septs (colony worlds) and are used to speed communications between outposts, since the T'au cannot rely on Astropathic messengers as they do not possess any psykers. These waystations typically consist of a core orbital module and a security module for defence.

Canon Conflict

When the T'au were first introduced into the Warhammer 40,000 universe, their vessels made use of a superluminal drive that still made use of the Warp in a limited fashion. According to the original version of T'au canon, at the time of the First Sphere Expansion, T'au vessels already used a form of gravitic propulsion called an Ether Drive.

This technology projected a sheath of gravitic energy ahead of and around the vessel which was continually re-projected further ahead, drawing the ship behind it rather like an archaic sail. For two hundred tau'cyr the Earth Caste unsuccessfully grappled with the problem only for the breakthrough to be handed to them.

On the innermost of T'au VII's moons a routine geological survey discovered the remains of an alien vessel. The significance of the find did not disrupt T'au society as much as might have been expected. T'au theorists had long reasoned that other intelligent life forms existed and the verification helped confirm the belief that there was a greater destiny awaiting them. No T'au commented on the unlikely good fortune of finding the technology that they so desperately needed on their doorstep just when they needed it.

The T'au were able to reverse-engineer and duplicate the Warp-Drive of the alien starship but the initial test flights were disastrous. Achieving transition to the Warp required more than technology, it required psychically attuned minds and the T'au race had developed no psykers. Without them to guide the transition, no amount of power could breach the dimensional barriers. The best the T'au could do was make a partial transition, forcing themselves into the void that separated Warpspace and realspace before they were hurled out again like a ball held under water, then released.

Data gathered at great cost during the test flights was studied closely. The Earth Caste scientists made the observation that the boundary between realspace and Warpspace was not a neat line. It was closer to a turbulent ocean fomented by the tempestuous Warp tides below. By carefully angling their descent toward the Warp and extending the field generated by the gravitic drive into a wing, shaped to hold the vessel down, a T'au vessel could extend the duration of the dive considerably.

The speeds achieved in the ascent back to realspace were staggering and this coupled with the effect of the Warp on space-time ensured that the real distance covered by this "Warp dive" was immense. Early tests lost several drone ships because they inadvertently passed far beyond the sensor range of their recovery vessels. The details were soon resolved.

There was still a major constraint, only the most powerful (and bulky) drives could sustain the gravitic wing throughout the dive and the power drain meant that considerable recharge time was needed between dives. Also by comparison to actually navigating the Warp the pace was still very slow. Compared to typical Imperial Warp speeds the T'au drive was slower by a factor of five. The speed was consistent though, did not continuously expose the T'au to the perils of the Warp and enabled the T'au to expand beyond their home star system for the first time.


  • Battlefleet Gothic - To Unite the Stars: Tau Vessels
  • Codex: Tau Empire (6th Edition), pp. 11-13
  • Death from the Skies (7th Edition), pp. 20-21
  • Imperial Armour Volume Three - The Taros Campaign, pg. 212
  • Battlefleet Gothic: Armada (Image) (PC Game)
  • Battlefleet Gothic Armada II (PC Game)


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