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University Library, University of Illinois at Urbana-Champaign

European Union Enlargement: Accession History & Current Member States

This topical guide explores the history and process of accession, enlargement, and integration to the European Union.

Current Member States & Accession Year

  • Austria - 1995
  • Belgium - 1958
  • Bulgaria - 2007
  • Croatia - 2013
  • Cyprus - 2004
  • Czechia - 2004
  • Denmark - 1973
  • Estonia - 2004
  • Finland - 1995
  • France - 1958
  • Germany - 1958
  • Greece - 1981
  • Hungary - 2004
  • Ireland - 1973
  • Italy - 1958
  • Latvia - 2004
  • Lithuania - 2004
  • Luxembourg - 1958
  • Malta - 2004
  • Netherlands - 1958
  • Poland - 2004
  • Portugal - 1986
  • Romania - 2007
  • Slovakia - 2004
  • Slovenia - 2004
  • Spain - 1986
  • Sweden - 1995

Map of EU Enlargement

A Brief Timeline of European Union History and Accession

The European Union is an organization that unites 27 European countries through common laws, economics, and security. The EU traces its origins to the desire for solidarity in the aftermath of World War II. 

  • 1949:  Establishment of the first pan-European organization, the Council of Europe, by founding members Belgium, Denmark, France, Ireland, Italy, Luxembourg, the Netherlands, Norway, Sweden, and the United Kingdom.
  • 1950s:  Establishment of the European Coal and Steel Community (ECSC), the European Economic Community (EEC), and the European Atomic Energy Community (Euratom). Member states of these three organizations include Germany, France, Italy, Netherlands, Belgium, and Luxembourg.
  • 1960s: European Free Trade Association (EFTA) is created
  • 1967:  The Merger Treaty is signed to combine three organizations - ECSC, EEC, and Euratom - into the European Communities.
  • 1973: Denmark, Ireland and the United Kingdom join the European Communities
  • 1981: Greece joins the European Communities
  • 1986: Spain and Portugal join the European Communities
  • 1993:  The European Union is born through the Treaty of Maastricht
  • 1994: The European Economic Area (EEA) is created
  • 1995: Austria, Finland, and Sweden join the European Union
  • 1997: The Treaty of Amsterdam lays plans to give Europe a stronger voice in the world and devote more resources to employment and the rights of citizens
  • 1999: The Euro is introduced
  • 2003: Treaty of Nice comes into force, reforming institutions so the EU can function efficiently after reaching 25 member countries and prepare for the next major group of new members joining
  • 2004: Czechia, Cyprus, Estonia, Latvia, Lithuania, Hungary, Malta, Poland, Slovenia, and Slovakia join the European Union
  • 2007: Bulgaria and Romania join the European Union
  • 2013: Croatia joins the EU
  • 2016: United Kingdom votes to leave EU

Case Study Resources: Cyprus

Case Study Resources: Greece