Water or Blood
The potential Emperor needs to have holy ground, specifically some of the red clay of Umar to be coronated. He also needs to build a power base to be able to dominate the houses the way his ancestors used to. He has sent the majority of his supporters and allowed other factions to send representatives (to gain strength). He has put it all under the Command of Naath Thrane, the other exiled great lord, in order to gain his support and aid.
Here is a list of theFactions of the Conquest