CIAM (Congres Internationaux d'Architecture Moderne), founded in Switzerland in 1928, was an avant-garde association of architects intended to advance both modernism and internationalism in architecture. CIAM saw itself as an elite group revolutionizing architecture to serve the interests of society. Its members included some of the best-known architects of the twentieth century, such as Le Corbusier, Walter Gropius, and Richard Neutra, but also hundreds of others who looked to it for doctrines on how to shape the urban environment in a rapidly changing world. In this first book-length history of the organization, architectural historian Eric Mumford focuses on CIAM's discourse to trace the development and promotion of its influential concept of the "Functional City." He views official doctrines and pronouncements in relation to the changing circumstances of the members, revealing how CIAM in the 1930s began to resemble a kind of syndicalist party oriented toward winning over any suitable authority, regardless of political orientation. Mumford also looks at CIAM's efforts after World War II to find a new basis for a socially engaged architecture and describes the attempts by the group of younger members called Team 10 to radically revise CIAM's mission in the 1950s, efforts that led to the organization's dissolution in 1959.