1958
Belgium, France, West Germany, Italy, Luxembourg and the Netherlands ratify the Treaty of Rome to create the European Economic Community (EEC).

They are building on the co-operation launched in 1951 as the European Coal and Steel Community. The six countries seek permanent peace in Europe, and the best conditions for economic success.

This first treaty defined the powers the member countries would give to the Community, and how it could use those powers. Subsequent treaties developed these powers to reflect the community’s enlargement and changing economic and social pressures.

1960s
Based in Brussels, the EEC flourishes. Other European countries press to join.

UK applications in 1961 and 1967 were both effectively vetoed by French leader Charles de Gaulle. It was not until de Gaulle was succeeded as President of France in 1969 that the French veto was lifted and negotiations with the United Kingdom began in earnest.

1970s
Britain’s Conservative government finally takes the country into EEC membership in 1973. (Ireland and Denmark also join).

In 1975 a new Labour government holds a national referendum designed to settle the argument about whether the UK should be part of the EEC.

The referendum backs UK membership by a 2-1 majority.

1980s/90s
Other countries continue to join.

Margaret Thatcher signs the Single European Act for the UK in 1986. The Act sets the aim of creating a single European market, for a free flow of goods and services between member states. It extends qualified majority voting to make it easier for the EEC to make laws in areas that support this goal.

The Soviet Union collapses, symbolised by the fall of the Berlin Wall in 1989. Europe begins to look a very different place.

In 1993 the Maastricht Treaty establishes the European Union which comprises the European Community and co-operation in the fields of common foreign and security policy and justice and home affairs. It also lays the foundations for a single European currency (the Euro).

In 1997 EU leaders signed the Treaty of Amsterdam which amended the Maastricht Treaty and the EC Treaty, extending the co-decision process and adding new provisions on social policy among other things.

1999
The Euro is created for its 11 members, but notes and coins are not yet circulated. The UK, Sweden and Denmark choose not to adopt the new currency; Greece does not meet the entry criteria. The Amsterdam Treaty enters into force.

2000
The Treaty of Nice is signed.

2002
Euro notes and coins are issued to replace the national currencies in 12 member states - Greece having joined in 2001.

2003
Treaty of Nice came into force.

2004
Eight Central and Eastern European nations join the EU, along with Cyprus and Malta.

Negotiations for a Constitutional Treaty conclude.

2005
EU starts membership talks with Turkey and Croatia, and recognises Macedonia as a candidate country.

Proposals for a Constitutional Treaty, designed to streamline processes in the enlarged EU, are rejected by referenda in France and the Netherlands. Member states enter a period of reflection on the best way forward for the EU.

June 2007
EU members agree to a mandate for the principles of a new treaty. The new treaty is intended to modernise the way the EU works, to enable an EU of 27 or more member states deliver more effectively for its citizens. Unlike the Constitutional Treaty, which would have repealed all existing EU treaties and replacing them with a single text, the new treaty will amend the existing treaties — like the Single European Act, Maastricht, Nice and Amsterdam treaties did.

05 Oct 2007
Draft version of the treaty is published, produced by EU lawyers working on the basis of the mandate agreed in June.

13 December 2007
The new Lisbon Treaty is signed by all 27 Member States. The Treaty will have to be approved by all EU countries, following their own constitutional procedures, before it can come into effect. In the UK, all Treaties, including EU Treaties, are submitted to Parliament, which has the right to examine and debate them in detail. The European Union (Amendment) Bill is introduced to Parliament on 17 December 2007.