My research at the Rockefeller Archive Center was conducted for my doctoral thesis which examines the history of the northern lowlands of Uganda's Albertine Rift Valley since the mid-nineteenth century. This area, which roughly corresponds to the modern-day district of Buliisa, has recently come to national and international attention as the location of some of the largest onshore crude oil fields discovered in Africa in the last few decades. Since the discoveries were made in 2006, conflict and tensions have arisen between and among communities, the state, and multi-national oil companies, over land, compensation and the anticipated revenues from the exploitation of this resource. But the lowlands have long been a site of struggle between different actors. It has for some time been the focus of particularly palpable, virulent, nervous and defensive strain of ethnic nativism. My thesis is a historical exploration of the ontological insecurity that has historically driven ethnic nativism and has itself been fuelled by ambiguity over ethnic self-identification and belonging in the valley. This study explores why this marginal place and the social identifications of the peoples who live there have become sites of unusually intense struggle.