For thirty years, the European Union has engaged in discursive practices and policy activities at the intersection of development policy and migration policy, thereby forging an EU migration-development nexus. The chapter introduces the main argument of the book: The inconsistencies that characterize the EU migration-development nexus may best be understood by focusing on the multiple EU policy actors active in the two classical policy fields that together comprise the nexus: EU development cooperation and EU migration governance. In addition, the chapter details the research questions of the book.