Oestala Prime System
The old sector capital, Oestala, is an unusual system. Oestala III and IV were both habitable, heavily populated worlds, and Oestala V's mineral wealth led to its colonisation for industrial purposes. This concentration of wealth and population in one system allowed it to maintain an organized government after the arrival of the warp storms. The ruling Sector aristocracy placated their large populations with the hope that the warp storms were only temporary, yet as year after year passed the limited resources on both Oestala III and IV began to grow increasingly strained. Eventually relations between the two hive worlds grew increasingly frosty. Eventually, Oestala III declared independence and sent a make-shift invasion force to take Oestala IV and V, Oestala IV responded by launching an orbital nuclear barrage against their former partner world - an action which Oestala III followed. Both are now dead worlds, with nothing but an irradiated wasteland left.
However, some of the old aristocracy managed to flee to Oestala V before the nukes arrived - so now you have super noble families stuck with the miners and proles. Shanty palaces were built so that the old sector aristocracy could relive the 'good ol' days' and throw elaborate parties. This lasted two generations, before the aristocracy were strung up by miners and factory workers. Whatever ambitions for a better life the commoners of Oestala V had, they've been buried under an Ork invasion. Now most live day to day, fighting what seems to be a never ending war against the Orkish tide. Every year the human survivors lose another habbloc, or manufactorum - weakening their ability to fight back bit by bit.