Southern Sudanese civilian populations have been trapped in a rising tide of ethnicised, South-on-South, military violence ever since leadership struggles within the main southern opposition movement – the Sudan People's Liberation Army (SPLA) – split into two warring factions in August 1991. This paper traces the devastating impact of this violence on a particularly volatile and fractured region of contemporary South Sudan: the oil rich heartlands of the Western Upper Nile Province. Foregrounding the historical experiences and grassroots perspectives of Nuer civilian populations in this region, the paper shows how elite competition within the southern military has combined with the political machinations of the national Islamic government in Khartoum to create a wave of inter- and intra-ethnic factional fighting so intense and intractable that many Nuer civilians have come to define it as ‘a curse from God’. Dividing Sudan's seventeen-year-long civil war (1983–present) into four distinct phases, the paper shows how successive forms and patterns of political violence in this region have provoked radical reassessments of the precipitating agents and ultimate meaning of this war on the part of an increasingly demoralised and impoverished Nuer civilian population.