Second Sphere of Expansion
The Second Phase of Expansion (018.M39- ~700.M41[1b]) was the second major phase of expansion for the Tau Empire, launched with the advent of the ZFR Horizon Accelerator Engine, which finally allowed the Tau to achieve long-range space travel.[1a]
With a faster fleet and armies bolstered by new Kroot allies, the Ethereal Supreme, Aun'Wei, declared a new phase of expansion ready. The campaign was launched from each of the new Septs established during the First Sphere of Expansion. In 053.M39, the Vespid were successfully integrated into the empire while in 393.M39 N'dras was colonized.[1b]. In 576, the first Battlesuits, the T-series prototypes, were deployed by the Tau.[1b] It was during this time that Commander Puretide achieved legendary fame for the Tau, scoring victories that led to the establishment of Septs such as Tash'var and Elsy'eir. Puretide went on to thwart an Ork invasion that threatened Au'taal. The last breakthrough of the Second Sphere of Expansion was the successful crossing of the Damocles Gulf, something that led to first contact with the Imperium. The destructive wars with Humanity that followed were unlike anything the Tau had experienced and brought an end to the Second Sphere of Expansion.[1a] New Septs established during the campaign included Au'taal, N'dras, Ke'lshan, Elsy'eir, Tash'var, Vash'ya, and T'olku.[1a]
Also in this period the Vior'la Sept's armies encountered a belt of lambent, crystal-rich asteroids and claimed them though only after the combat with some mechanical foes that fade from sight when slain.
- 1: Codex: Tau Empire (6th Edition)
- 2: Codex: Tau Empire (7th Edition), pg. 40, Relentless Expansion - Conquest and Mustery