Out of all the mortal civilisations of the world, no single race, neither the ruthless Human barbarian tribes of the north nor the savage Greenskins of the east can be compared in terms of instability to that of the Skaven Under-Empire. The Skaven race as a whole is extremely divided, often far more divided than perhaps any other race known in existence. Such disunion and ruthless lack of cooperation stems from the Skaven's insatiable need to survive, thrive, and reign tyrannically over his brethren.[1e]