Dutch architect and planner Cornelis van Eesteren served as president of CIAM, the Congrès International d'Architecture Moderne, from 1930 to 1947. His tenure there was steady and influential, but has been little studied, as the rise of Team 10 and then CIAM itself as a global force in the 1950s have obscured the organization's roots as a cooperative that was first embraced by its Dutch and Swiss members. The city analyses that CIAM members conducted for their 1933 congress, chaired by van Eesteren, made an important contribution to what they called "comparative town planning." "The Functional City" focuses on that legendary fourth congress, held in the summer of 1933; examines van Esteren's legacy; and traces CIAM's early evolution through an abundance of little-known archival material. The leitmotif in this narrative is the principle of collectivity: the avant-garde ideal of concerted action as the basis for the creation of a thoroughly contemporary human habitat.