FACTBOX - Milestones in EU history

(Reuters) - European Union leaders meet this week to approve a new treaty reforming the 27-nation bloc's creaking institutions and replacing the defunct European constitution.

Below are some of the key dates in EU history:

March 25, 1957 - Six founders -- France, Germany, Italy, the Netherlands, Belgium and Luxembourg -- sign Treaty of Rome establishing European Economic Community (EEC), a common market with free movement of goods, capital, labour and services.

July 1958 - Principles of the Common Agricultural Policy (CAP) set by the Stresa conference and come into force in 1962.

July 1, 1967 - European Community (EC) formed by merging the EEC with the European Atomic Energy Community (Euratom) and the European Coal and Steel Community (ECSC), both created by the same six founder nations.

January 1973 - Britain, Denmark and Ireland join. Norway votes not to join.

1978 - European Council created as a regular meeting of heads of state and government, without legislative powers.

March 1979 - Exchange Rate Mechanism (ERM) is formed, linking German mark, French and Belgian francs, Dutch guilder, Danish crown, Irish punt and Italian lira within narrow bands.

January 1981 - Greece becomes the 10th EC member.