From its foundation in 1957 to its self-dissolution in 1972, the Situationist International established itself as one of the most radical revolutionary organisations of the twentieth century. This book brings together leading researchers on the SI to provide a comprehensive critical analysis of the group's key concepts and contexts, from its relationship to earlier artistic avant-gardes, romanticism, Hegelianism, the history of the workers' movement and May '68 to the concepts and practices of 'spectacle', 'constructed situations', 'everyday life' and 'détournement'. The volume also considers historically underexamined areas of the SI, including the situation of women in the group and its opposition to colonialism and racism. With contributions from a broad range of thinkers including Anselm Jappe and Michael Löwy, this account takes a fresh look at the complex workings of a group that has come to define radical politics and culture in the post-war period.