- Simon Bulmer, Simon BulmerProfessor of Politics, University of Sheffield
- Owen Parker, Owen ParkerLecturer in European Politics, University of Sheffield
- Ian Bache, Ian BacheProfessor of Politics, University of Sheffield
- Stephen GeorgeStephen GeorgeEmeritus Professor of Politics, University of Sheffield
- and Charlotte BurnsCharlotte BurnsProfessor, University of Sheffield
This chapter first examines the European Union’s (EU’s) main enlargement rounds. The first enlargement occurred in 1973 when Britain, Denmark, and Ireland were admitted as members. The second (1981) and third (1986) enlargements are often treated as a single ‘southern enlargement’. The fourth enlargement took place in 1995, and admitted Austria, Finland, and Sweden. The fifth and sixth enlargements, in 2004 and 2007, are known as the ‘eastern enlargement’. The seventh enlargement saw the admittance of Croatia in 2013. A number of further states in the western Balkans are at various stages in their accession processes. The chapter describes what happened during each round and the evolution of the procedure for joining. It reviews academic explanations of why the various applications for membership were made, and why they were accepted by the European Community (EC)/EU. Finally, the chapter looks at the controversial case of Turkey and considers the notion of ‘enlargement fatigue’.