The Tiro'fal system is a sept situated on the ever growing borders of tau space. First settled during the late Second Phase Expansion as an attempt to expand beyond the Perdus Rift, the sept pushed the borders of the Tau Empire, settling near the territory of the Kroot worlds. The sept came under attack in late M41 and was declared under quarantine by the Ethereal Caste, the sept's Fire Warriors leading a valiant defence of the other castes' escape.