This paper examines the emergence and intensification of a “border crisis” along Egypt’s western frontier in the first decades of the twentieth century. Although the western boundary of Egypt is a topic that has received strikingly little scholarly attention in the historiography of modern Egypt, I suggest that it is actually a crucial lens through which to explore broader questions of sovereignty, identity, and statecraft in Egypt and the late Ottoman Empire in the decades prior to the First World War. My narrative begins in 1902 when the Ottoman Government established a military presence at the Mediterranean port of Sollum, which Istanbul claimed was not in fact on Egyptian soil. This Ottoman military occupation kicked off a storm of events that ultimately added up to the appearance of crisis along the border, sending the Egyptian Government into a panic and simultaneously drawing in the British and Italian authorities, who were concerned about their own strategic imperatives in the region. Drawing on an array of Italian, Ottoman, and British archival sources, my paper seeks to reconstruct this pivotal series of events through to 1916, when the British military succeeded in quashing a Western Desert rebellion spawned by the Libyan-based Sanusi Islamic brotherhood. The main objective of the paper is not merely to account for the complicated series of diplomatic exchanges surrounding the frontier crisis, but rather to understand the crisis from the point of view of the various Bedouin tribes who inhabited the borderland. Many of these tribes managed to capitalize on the border crisis for their own advantage, harnessing the countervailing diplomatic forces to help resolve a recent spate of local cross-border disputes in their favor. At the same time, the various tribes invoked or flouted the border as necessary, and otherwise worked alternately with Egyptian, Italian, British, and Ottoman officials as it suited their needs. Ultimately this paper seeks to underscore the interactivity between this array of state and non-state actors in order to reconceptualize Egyptian history at its western frontier, and to demonstrate how this particular border episode illuminates the Ottoman-Egyptian relationship.