40K Lore: Kor’vattra – the T’au Navy

Gather round Admirals –  today we explore the T’au Empire’s fleet and the Air Caste who command it.

The Tau Fleet (known as Kor’vattra in the Tau language) is responsible for the defense of the Tau Empire and their stellar expansion plans. Tau vessels are operated by the Air Caste.


The Tau Empire has only expanded into space during the last millenium. 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 Tau fleet has been given the highest priority by the Ethereal Caste. By M39 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, however, and this proved to be a formidable barrier.

Warp Technology

Tau vessels were already equipped with a form of gravitic drive. This system 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 grappled with the problem, only for the breakthrough to be handed to them. On the innermost of T’au Seven’s moons, a routine geological survey discovered the remains of an alien vessel. The significance of the find did not disrupt Tau society as much as might have been expected. Tau theorists had long reasoned that other life forms existed and the verification helped confirm the belief that there was a greater destiny awaiting them. It seems that no Tau commented on the sheer good fortune of finding the technology that they so desperately needed on their doorstep just when they needed it.

The Tau were able to replicate the warp drive of the alien vessel but the initial test flights were a disaster. Achieving transition to the Warp required more than technology, it required psychically attuned minds and the Tau race boasted no psykers. Without them to guide the transition, no amount of power could breach the dimensional barriers.

The best the Tau could do was make a partial transition, forcing themselves into the void that separated Warp space and real space 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 real space and warp space was not a neat line. It was closer to being 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 Tau vessel could extend the duration of the “dive” considerably. The speeds achieved in the ascent back to real space were staggering and this, coupled with the effect of the Warp on time and space, ensured that the real distance covered by the 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 Tau drive was slower by a factor of five. The speed was consistent though, did not expose the Tau to the perils of the Warp and enabled the Tau to expand beyond their home star for the first time.

Ship Development

The first major class of Starships built were the ponderous Gal’leath (Explorer) class vessels. These vessels laid the foundations for the Tau Empire and formed the basis of the Kor’vattra for its first wars with the Orks and the Nicassar. The Nicassar were less advanced than the Tau and after their speedy defeat were one of the first other races absorbed into the Empire. The Orks, however, posed a major problem: Ork ships were faster, better shielded and more heavily armed. The Gal’leath class was simply too expensive a resource to risk against such a dangerous adversary. Fortunately new, more compact gravitic drives led to the introduction of the smaller Il’fannor (Merchant) class and, to counter the numerous Ork escorts, the Tau developed their own Kass’l (Orca) gunships. The Tau were slow to build a gravitic drive with sufficient power for Warp drives small enough to create an independent escort, so the Kass’l would travel inside a larger vessel’s gravitic sheath over long distances, disengaging when back in normal space. This, combined with the introduction of super-heavy Ion cannons and Barracuda fighters, helped restore the balance – but it was the power and efficiency of the Tau shipyards that prevented the Empire from being devastated.

Kor’or’vesh Initiative

Naval engagements with the Imperial Navy during the Damocles Crusade were unfavorable to the Tau, particularly the losses they sustained in their first battle in the Tau-claimed Hydass System. Additional losses against tendrils of Hive Fleet Behemoth immediately afterward demonstrated to the Tau that despite the Kor’vattra’s valor, it was out-gunned, out-maneuvered, and required better hardware and reevaluation of its doctrines.

With the full blessing of the Ethereal Caste, Tau High Command began a bold fleet expansion and development program. entitled Kor’or’vesh that would see new ship designs, built with the newest of Tau technology, and informed by the costly losses they had already sustained. The program was given the highest priority, applying the best of the Earth Caste engineers to the project and sparing no expense in resources. The result were several new classes of Tau ships, 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 Carrier Escorts. While individual craft from this program were encountered by Imperial forces prior, the Taros Campaign was the first time multiple examples of these new generation Tau ships would see battle against the Imperium.

Ships of the T’au Navy

~Report to the bridge Admiral!

  • abaddonsmummy

    In the first picture at the top of the page the red ships in it look like the Harkonnen Ships from Dune.


    • zeno666

      GW has stolen a lot from Dune

      • Tshiva keln

        I think you will find they didn’t. Clearly Dune committed a “preemptive infringement” of GW IP. Their lawyers are looking into it.

        • zeno666

          Of course, silly me!
          GW can’t do no wrong 😉

          • Tshiva keln

            Don’t know if the double negative was intentional or not but it made me smile either way.

  • James Regan

    interesting how encountering orks was so tough, as ork planetary defence is largely based of the fact you have to practically destroy the planets biosphere to win the ground war (or have the manpower to fight it forever, al la the orks hunters of armageddon’s jungle regions). It’s worth noting that removing orks from an invaded planet, while still tough, is probably much easier than destroying them on a world that’s settled- ork species form their own invasive ecosystem, given they photosynthesise and so don’t particularly need native plants in the long run, which means you have to strip the biosphere more or less completely, which mean, unless you are the hive mind, you’re left with a world that needs terraforming as you’ve just put it right back outside the habitable zone for humans etc. (even with the imperiums dark age of tech bio-engineering meaning the species is less… focussed in 40k)

    • Ryan Miller

      The thing is, orks spore constantly and then when they die they spore harder. Exterminatus is the only way! Just like turanids.

    • Mike Tbone Green

      im very sure the Tau found a way to kill the spores.

      • James Regan

        you can kill the spores, sure, but in a world that’s primary poulation is orks, orks are the biosphere, which means you are doing exterminatus in all but name- you burn, or virus bomb, or regular bomb, the entire surface of the planet, as there won’t be much left living that isn’t just more ork.

  • Drpx

    Why the heck isn’t BFG coming back?