During the 8th cult invasion of Arignen, Arssasstur(need to review the chronology but ruled 16 years pre TKR) the head oligarch of Arignen, emperor of the ancient (originally native) Arignite empire fell to the mounted Yalanturides in battle. In an island located off the main capitol city of the subcontinent, the site was made into a new temple of tchmut. The site of the initial amphibious landings by the 8th cult which took the capitol of the empire.
When the 8th cult took power anyone who was remotely capable of posing a threat to the TKR in an area conquered during its rise was purged early on Servant uprisings happened in early days after an area began purification (have the exact terminology somewhere) Though the claims of continuity with pre tchmutic nobility by TKR elites were true. Survivors of initial purges were given ascendance to their rule in the TKR as selected by the seven and preists of Tchmut.