8 December 2011
Last updated at 15:13
The Treaty of Paris in April 1951 brought together six countries - France, West Germany, Italy, Belgium, Luxembourg and the Netherlands - for the creation of the European Coal and Steel Community. What started as a free trade area in the aftermath of World War II for coal, coke, steel, scrap and iron ore eventually led to a union of 27 members. They set up four major institutions: a nine-member High Authority to supervise the market, a Council of Ministers to legislate, an Assembly of 78 members from national parliaments, and a Court of Justice of seven judges to interpret the treaty and resolve related disputes.
Six years on, the founder members of the coal and steel community set up through The Treaty of Rome (25 March 1957) the European Economic Community (EEC) as well as the European Atomic Energy Community (Euratom).
The first reform of the Treaty of Rome took place in 1965 with The Merger Treaty signed in Brussels. Three councils of ministers(from the EEC, the coal and steel community and Euratom) were merged into a single Council while the two executives of Euratom and the EEC became one Commission.
The Single European Act, signed in February 1986, was a major revision of the Treaty of Rome that broadened the powers of the Commission, increased the role of the European Parliament, set up the framework for a Single European Market, and laid the ground for a European foreign policy.
The Maastricht Treaty (10 December 1991) officially changed the European Community into the European Union. Maastricht significantly set out a timetable for economic and monetary union and a social chapter, covering workers' pay, and health and safety at work. The three pillars of the Union were set up - adding cooperation between governments on judicial and home affairs as well as foreign and security policy to the supranational framework of the European Community.
The European internal market was completed by the Treaty of Amsterdam 1997. The passport-free Schengen agreement became EU law (without UK and Ireland), and the European Parliament was given powers on a series of issues in co-operation with the Council of Ministers. A community employment policy was established and the UK dropped its opt-out of the social chapter.
The Nice Treaty in December 2000 set out expansion of the EU from 15 to (eventually) 27 members. Importantly, a limit was placed on the number of European commissioners and MEPs. National governments lost their veto in a number of policy areas in the Council of Ministers. But vetoes remained in tax and social policy.
The Lisbon Treaty (signed 13 December 2007) aimed to streamline EU institutions to make a larger 27-member union work better. But it became law only in Dec 2009 after a difficult period of ratification, including two Irish referendums. Under the treaty, the Commission, parliament and Court of Justice were given new powers - with MEPs given equal footing with the European Council. A president was created for the Council as well as a new EU foreign affairs chief.