1945 - Second World War ends. (Deaths in EU countries were Germany 7 , Poland 6 , France 0.6 , Italy 0.5 and UK 0.5 million.)
1952 - Treaty of Paris (1951) between 6 countries - Belgium, France, Germany, Italy, Luxembourg and the Netherlands - enters into force. European Coal and Steel Community (ECSC) created. The aim was to prevent territorial disputes over natural resources - one of the causes of the Second World War.
1958 - Treaties of Rome (1957) enter into force. European Atomic Energy Community (Euratom) and European Economic Community (EEC - later renamed the European Community - the EC) created.
1973 - Denmark, Ireland and the UK join the communities. Total now 9.
1974/5 - Greek, Portuguese and Spanish military dictatorships end ... whereupon ...
1981 - ... Greece joins, and then ...
1986 - ... Portugal and Spain join. Total now 12.
1987 - Single European Act (1986) enters into force.
1993 - Maastricht Treaty (1992) enters into force. European Union (EU) created.
1993 - Single Market ‘completed’.
1995 - Austria, Finland and Sweden join the EU, bringing the total to 15.
1999 - Amsterdam Treaty (1997) enters into force.
1999 - Economic and Monetary Union starts.
2000 - Pre-enlargement Inter-Governmental Conference (IGC) starts.
2002 - Treaty of Paris (and hence the ECSC) expires.
2002 - Introduction of Euro coins and notes.
2004 - Enlargement:- Cyprus, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, Slovenia all join, bringing the total to 25.
2007 - Bulgaria and Romania join, bringing the total to 27.
2010 - The Lisbon Treaty (Treaty on the Functioning of the European Union - TFEU) comes into force. European Community and European Atomic Energy Community abolished.
2013 - Croatia joins, bringing the total to 28.
2016 - (23 June) UK votes to leave the EU
2017 - (29 March) UK gives notice of its intention to leave the EU
2017 - (8 December) UK and EU agree outcome of Phase 1 of Brexit negotiations