The 1947 partition of British India, culminating in the demarcation of the Radcliffe Line, ranks among the most violent exercises in border-making of the twentieth century. Drafted within the compressed timetable of imperial withdrawal, the boundary was produced in barely five weeks by Sir Cyril Radcliffe, a barrister with no prior knowledge of the subcontinent. Although presented as a neutral effort to balance demographic and economic considerations, the Radcliffe Award in practice reflected Britain’s determination to preserve imperial prestige rather than to ensure lasting stability. Overnight, entire communities were divided, unleashing the forced migration of more than ten million people and resulting in at least half a million deaths. While nationalist rivalries aggravated the upheaval, its structural conditions derived from the colonial state’s long-standing divide-and-rule strategies and the haste of decolonization. The Radcliffe Line endures as a paradigmatic instance of imperial cartography generating lasting frontiers of violence, displacement, and contested sovereignty in South Asia.