This “case studyâ€ examines the shaping of a research interest. It turns on the Partition of the South Asian subcontinent in 1947, leading to the Independence and establishment of the sovereign states of Pakistan and India. The Partition was a climax within a pattern of recurrent violence in the name of Hindus and Muslims for several generations before 1947, a pattern that recurs at lower intensity continually. This study explores the emerging of an interest in the social origins of the Partition out of several decades of the author’s personal experience. It tracks the origins of a sense of difference between the religiously defined social categories to the medieval period--though the Mughal period saw wide-ranging cooperative activity too. The colonial period saw a major change of phase, with heightened insecurities amidst large changes in polity, economy, and society, and the rise of influential institutions for religious revival on both sides. Amidst comprehensive enlargements in the scales of organisations, communications, and activities, the sense of opposition between groups, defined in religious terms, grew; and so too the frequency and intensity of aggression across the divide. The violence in 1947 was exceptionally brutal and large in scale; but the underlying attitudes had long been in the making. To take full measure of that long inception, one needs to summon the resources not only of history but also of a wide array of other social sciences.