This PhD thesis explores the use of symbolism in European integration during the 1950s and 1960s. The thesis argues that political elites staged the early European Communities - the 1952 ECSC as well as the 1958 EEC and Euratom - as the representation of a united Europe and so tied them to a vision with much momentum in post-war Europe. This symbolic role of the Communities transcended their technocratic set-up and their narrow economic policies: it made them distinctive among the many post-war European organizations. Empirically, this thesis focuses, in separate parts, on three settings where the Communities were staged as the united Europe: the Communities’ parliamentary assem-blies (first part), the Communities’ diplomatic activities (second part), and the Communities’ polycentric seating arrangements (third part). This thesis deals with a wide array of actors who, for different reasons, participated, actively or tacitly, in the staging of the Communities: the news media and occasionally also civil society actors, governments and administrations, parties and parliaments across the original six member states as well as those of the Communities’ external partners, Britain and the United States. Conceptually, this thesis presents a cultural history approach to European integration. It aligns itself with a new strand of research in European integration history that aims to go beyond the much-advanced diplomatic history of the European Communities and to add to it an interest in discourses, identities, and symbols. With its study of symbolism, this thesis seeks to bring together the literature on the diplomatic history of the European Communities and the intellectual history of the European idea; it also seeks to help historians define the nature of the European Communities and assess their place in post-war European history. This thesis is based on the papers of Jean Monnet and Walter Hallstein, two key figures of the early European Communities, and archival materials from the Historical Archives of the European Union in Florence as well as the diplomatic archives of France and Germany, Britain and the United States.