The EU grew from six founding countries in 1958 to 28 in 2013 through seven enlargements, the largest being ten countries in 2004. It went down to 27 when the United Kingdom left on 31 January 2020.
The European Economic Community started on 1 January 1958 with six countries: Belgium, France, Germany (then West Germany), Italy, Luxembourg and the Netherlands. Since then, membership has changed in successive waves.
- 1973: Denmark, Ireland and the United Kingdom join (9 members).
- 1981: Greece joins (10).
- 1986: Portugal and Spain join (12).
- 1995: Austria, Finland and Sweden join (15).
- 2004: Cyprus, Czechia, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia join (25), the largest enlargement.
- 2007: Bulgaria and Romania join (27).
- 2013: Croatia joins (28).
- 2020: the United Kingdom leaves on 31 January (27).
Several enlargements followed major political changes. The European Parliament notes that the accessions of Greece in 1981 and of Portugal and Spain in 1986 consolidated democracy in those countries. The 2004 enlargement was intended to reunite the continent after the fall of the Berlin Wall and the collapse of the Soviet Union. Since the 2000s, conditions have become stricter: Croatia’s negotiations were subject to the tighter rules agreed by the European Council in 2006.
Territory has also changed without new member states. When Germany reunified on 3 October 1990, the former East Germany became part of the European Communities through reunification, without a separate accession. Greenland, part of the Kingdom of Denmark, joined in 1973 with Denmark but left the European Communities on 1 February 1985.
Example
The 2004 enlargement shows how long the process can take. It was launched by the European Council in December 1997, and negotiations were conducted separately with each country, on a single framework. Ten countries, eight of them in Central and Eastern Europe plus Cyprus and Malta, joined on 1 May 2004.
Debates and limits
Not every country that negotiated joined. Norway took part in the negotiations of the early 1990s but rejected accession in a 1994 referendum, with 52% against. Enlargement remains debated: supporters see it as a way to spread stability and democracy, while critics worry about the EU’s capacity to absorb new members and keep taking decisions efficiently. The European Council itself made the EU’s “integration capacity” one of the conditions of enlargement in 2006.