Chapter 1 introduces the rising power of interest groups in education, provides a brief literature review, and poses the research questions. This is followed by a section on institutional theory and how vested interests fit within this research programme and how this is applied to education policy. The chapter also presents key educational interest groups, their origins and causes, and the different types of mediation systems, detailing the traditional relationships between the state and these groups across the case countries and the European Union. Thereafter, there is a brief section on method and an overview of the chapter structure of the book.