Treaties of the European Union the Functioning of the European Union (originally signed in Rome in 1957 as the Treaty establishing the European Economic Community, aka The Treaty of Rome), lay out how the EU operates, and there are a number of satellite treaties which are interconnected with them. The treaties have been repeatedly amended by other treaties over the 65 years since they were first signed. The consolidated version of the two core treaties is regularly published by the European Commission. The two principal treaties on which the EU is based are the Treaty on European Union (TEU; Maastricht Treaty, effective since 1993) and
2016 United Kingdom European Union membership referendum or Euratom) and European Economic Community (EEC) in 1957. The EEC, the more ambitious of the three, came to be known as the "Common Market". The UK first applied to join them in 1961, but this was vetoed by France. A later application was successful, and the UK joined in 1973; two years later, the first ever national referendum on continuing membership resulted in 67.2% approval. Political integration gained greater focus when the Maastricht Treaty established the European Union (EU) in 1993, which incorporated (and after the Treaty of Lisbon, succeeded) the European Communities. Prior to the 2010 general election,