Development of the European Union – A Timeline

The European Union Flag
The European Union Flag. Public Domain

This timeline is designed to complement our short history of the European Union.


1923: Pan European Union society formed; supporters include Konrad Adenauer and Georges Pompidou, later leaders of Germany and France.
1942: Charles de Gaulle calls for a union.
1945: World War 2 ends; Europe is left divided and damaged.
1946: European Union of Federalists forms to campaign for a United States of Europe.
September 1946: Churchill calls for a United States of Europe based around France and Germany to increase chance of peace.
January 1948: Benelux Customs Union formed by Belgium, Luxembourg and Netherlands.
1948: Organisation for European Economic Co-operation (OEEC) created to organise the Marshall Plan; some argue this is not unified enough.
April 1949: NATO forms.
May 1949: Council of Europe formed to discuss closer co-operation.


May 1950: Schuman Declaration (named after the French Foreign Minister) proposes French and German coal and steel communities.
19 April 1951: European Coal and Steel Community Treaty signed by Germany, France, Ireland, Luxembourg, Belgium and Netherlands.
May 1952: European Defence Community (EDC) Treaty.
August 1954: France rejects the EDC treaty.
25 March 1957: Treaties of Rome signed: creates Common Market / European Economic Community (EEC) and European Atomic Energy Community.
1 January 1958: Treaties of Rome come into effect.


1961: Britain tries to join the EEC but is rejected.
January 1963: Franco-German Treaty of Friendship; they agree to work together on many policy issues.
January 1966: Luxembourg Compromise gives majority vote on some issues, but leaves national veto on key areas.
1 July 1968: Full customs union created in the EEC, ahead of schedule.
1967: British application again rejected.
December 1969: Hague summit to “relaunch” the Community, attended by heads of state.


1970: Werner Report argues economic and monetary union possible by 1980.
April 1970: Agreement for EEC to raise own funds through levies and customs duties.
October 1972: Paris Summit agrees plans for future, including economic and monetary union and ERDF fund to support depressed regions.
January 1973: UK, Ireland and Denmark join.
March 1975: First meeting of the European Council, where heads of state gather to discuss events.
1979: First direct elections to European Parliament.
March 1979: Agreement to create the European Monetary System.


1981: Greece joins.
February 1984: Draft Treaty on European Union produced.
December 1985: Single European Act agreed; takes two years to ratify.
1986: Portugal and Spain join.
1 July 1987: Single European Act comes into effect.


February 1992: Maastricht Treaty / Treaty on European Union signed.
1993: Single Market begins.
1 November 1993: Maastricht Treaty comes into effect.
1 January 1995: Austria, Finland and Sweden join.
1995: Decision taken to introduce the single currency, the Euro.
2 October 1997: Treaty of Amsterdam makes minor changes.
1 January 1999: Euro introduced in eleven counties.
1 May 1999: Treaty of Amsterdam comes into effect.


2001: Treaty of Nice signed; extends majority voting.
2002: Old currencies withdrawn, ‘Euro’ becomes sole currency in majority of EU; Convention on the Future of Europe created to draw up constitution for larger EU.
1 February 2003: Treaty of Nice comes into effect.
2004: Draft constitution signed.
1 May 2004: Cyprus, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovak Republic, Czech Republic, Slovenia join.
2005: Draft constitution rejected by voters in France and the Netherlands.
2007: Lisbon Treaty signed, this modified the constitution until it was deemed a sufficient compromise; Bulgaria and Romania join.
June 2008: Irish voters reject Lisbon Treaty.
October 2009: Irish voters accept Lisbon Treaty.
1 December 2009: Lisbon Treaty comes into effect.
2013: Croatia joins.
2016: United Kingdom votes to leave.