Treaty of Rome in 2009, the Treaty of Lisbon renamed it the "Treaty on the Functioning of the European Union". The TFEU originated as the treaty establishing the European Economic Community (the EEC treaty), signed in Rome on 25 March 1957. On 7 February 1992, the Maastricht treaty, which led to the formation of the European Union, saw the EEC Treaty renamed as the Treaty establishing the European Community (TEC) and renumbered. The Maastricht reforms also saw the creation of the European Union's three pillar structure, of which the European Community was the major constituent part. Following the 2005 referenda, which saw the
Accession of the United Kingdom to the European Communities Accession of the United Kingdom to the European Communities The Accession of the United Kingdom to the European Communities (EC) – the collective term for the European Coal and Steel Community (ECSC), the European Economic Community (EEC) and the European Atomic Energy Community (EAEC) – took effect on 1 January 1973. This followed ratification of the Accession treaty which was signed in Brussels on 22 January 1972 by the Conservative prime minister Edward Heath, who had pursued the UK's application to the EEC since the late 1950s. Denmark and Ireland also joined as part of the same expansion but Norway,