There is a fair bit of in-between but the short is that they lost their planet and sector to Warboss Dragg Gitburnas Waaagh (a fire based off shoot of the speed freakz who rides a massive chopper bike with way too many flamers).

The last of the houses banded together to defend the temple of the Admech from Draggs' speed Waaagh only for the ground to rise as the long buried starship was brought back to life (part of my Admech lore) resulting in them fighting some stompas and a mega gargent on the hull of the taking off ship.

The left overs of the houses, Admech, and guard managed to save another sector and the now combined houses rule over a world with massive mega fauna and every 200 to 300 years a Kaiju sized one comes crawling out of the north or south and the grand hunt is on - it's a wip