This paper examines the imperial policy-making process that led to a textual separation of Sudan from Egypt in the wake of Britain’s defeat of the Mahdi insurrection. British officials drew two lines were drawn on a map. The first, a straight border along the 22° latitude drawn in 1899, allowed the British ruler in Cairo, Lord Cromer, to now define Sudan simply as ‘south of the parallel’. A second border, conceptualised in 1902, made some adjustments which brought regions north of the line (Wadi Halfa, Hala’ib) under the control of British officials in Khartoum, while extending Cairo’s administrative responsibility southward over a small bulge of land in between (Bir Tawil). These competing lines on a map did not depict any natural, pre-existing boundaries: they rarely do, of course, nor are they ever meant to (see, e.g. James Scott,1998). Rather, they represent the multiple frontiers which existed in the colonial imagination (see e.g. Lord Curzon, Lord Cromer). This paper shows how these new spatial constructions were intentionally nebulous in order to allow Britain to both recognize Egyptian claims and exclude European ones (e.g. the capitulations), all the while ensuring that the empire maintains secure control over the entire Nile River ecosystem. But the significance of these competing borders goes further than can be captured in the archival record of the colonial officials who were responsible for marking these dividing lines on a map. Drawing on conceptual debates in the field of border studies or ‘borderlands’, ‘borderscapes’ (inter alia, G. O Tuathil, A. Paasi, C. Brambilla, J.P. Laine) this paper also examines the changing ways in which the two lines have been experienced, exploited and perceived by successor regimes in Cairo and Khartoum, in the years since (with a particular focus on the last decade). --- Brambilla, C. “Exploring the Critical Potential of the Borderscapes Concept” in Geopolitics, Vol20, No.1 (2015) Cromer, Modern Egypt (MacMillan, 1911). Curzon, Frontiers (Clarendon Press, 1907). Laine, J.P. “Understanding Borders under Contemporary Globalisation, in Annales Scienta Politica Vol.6, No.2 (2017). O Tuathil, G. Critical Geopolitics: the Politics of Writing and Global Space (University of Minnesota Press, 1996). Paasi, A. Territories, Boundaries and Consciousness (Wiley, 1996). Scott, J. Seeing Like a State: How Certain Schemes to Improve the Human Condition have Failed (Yale University Press, 1998).