Perhaps the House Wars could be a RESULT of the Empire's collaspe.
As otherwise the legion *will* step in stop any open warfare. With the Empire aroudn the only house wars are quiet skirmishes in the ashlands and assassinations, like in morrowind.
Oh. And for Future Referance, heres a map of the known World:
clickSo we know some geography.

I'd rather like to stick to morrowind. MW's mainland and Vvardennfell are large enough...
