What is a refugee camp? Existing definitions have focused on logics of power and institutions of governance. This article argues instead that refugee camps are best understood in relation to their purpose of containment. It posits ‘camps of containment’ as a specific form of encampment consisting of three primary categories: prisoner-of-war camps, internment camps and camps for forced migrants. This genealogy sheds new light on the origin of the refugee camp and reveals camps of containment to be an evolving politico-military strategy related to changing patterns of political conflict and to shifting anxieties about national security.