The Human Terrain System. Modern population-centric COIN doctrine. The ‘Big Data’ phenomenon. All of these things reflect a similar preoccupation, namely the need to develop forms of understanding that can provide outsiders with influence and control over a resistant society or elements therein, and which allow relatively small numbers of counterinsurgents to deliver ‘stability’. Yet despite the modern terminology and the association with largely twenty-first-century conflict, these concepts are part of an intellectual trajectory that stretches from the high renaissance of European imperialism in the eighteenth and nineteenth centuries, through the Cold War to today. On the British frontier of India, in the US-controlled Philippines or in colonial French Indochina and North Africa the task was similar to that faced in Vietnam, Iraq or Afghanistan: to push into unknown territory; to generate influence and understanding there; to defeat rebellion; to fundamentally change that which already existed or to build relationships with local elements who could support one’s own political or strategic objectives. The result was (and is) a series of developments and practices that have, over time, found their expression in the form of contemporary COIN and stabilisation theory and doctrine.