The Conclaves fought a long and vicious war with Ursh, in which they were defeated. It is said that Nordafrik had access to much higher technologies than Ursh, so the Urshite overlord Kalagann fought them not only for for reasons of pure conquest but also out of sheer envy. The war was described in the Chronicles of Ursh, which detailed the bloody conflict which ended in a battle for the so-called murengon (walled sanctuary) of Xozer. There dark powers of the Warp were used by both sides when Nordafrik's hierophants clashed with Urshite wrathsingers. Only one of the wrathsingers - their commander Mafeo Orde - survived the massacre; not a single hierophant was left alive and the murengon was destroyed completely.
Later in history this region became known as the Nordafrik under-archives. Some time after the formation of the Great Rift it was discovered that a Genestealer Cult known as the Wyrms of the Ur-Tendril was active in the region. The cult was subsequently defeated by the Adeptus Custodes.