This chapter will present both a history of the concentration camp and a consideration of why this institution is so important to modern consciousness and identity. Briefly tracing the concentration camp’s origins in the colonial wars of the late nineteenth and early twentieth centuries, it then stresses the significance of World War I, which saw the internment of civilians and POWs on a large scale. It then examines the Nazi camp system and the Stalinist “Gulag” and compares the totalitarian countries’ use of camps with those of other, neglected settings, such as the American internment of Japanese-American citizens during World War II, Franco’s camps during and after the Spanish Civil War, Britain’s use of camps for Jewish DPs in Cyprus trying to reach Palestine after World War II, and the colonial powers’ resort to camps during the wars of decolonization, such as in Kenya. By offering a survey of the history of concentration camps in a global setting, the chapter is then able to engage with the philosophical literature dealing with the question of what the camps tell us about the nature of the modern world.