This chapter examines the integration of national social-security schemes that has taken place in the European Union through Community Regulation 1408/71. It seeks to demonstrate that a dimension of European social security has for long been a material fact, patched up by judicial activism and political compromises. The chapter is divided into five main parts. First, it introduces the European dimension of welfare as established through social-security coordination. Second, the chapter describes the europeanization process of migration control and access to national welfare. The third part asks to whom intra-European social security applies. The fourth part of the chapter analyses in greater detail the extent to which welfare has been de-territorialized in the EU. The last part provides some concluding remarks on the evolution of the European dimension of social security, and the relation between law and politics in the course of welfare integration.