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
European Economic Community the European Economic Area covering 15 countries. Upon the entry into force of the Maastricht Treaty in 1993, the EEC was renamed the "European Community" to reflect that it covered a wider range than economic policy. This was also when the three European Communities, including the EC, were collectively made to constitute the first of the three pillars of the European Union, which the treaty also founded. The EC existed in this form until it was abolished by the 2009 Treaty of Lisbon, which incorporated the EC's institutions into the EU's wider framework and provided that the EU would "replace