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
2004 enlargement of the European Union countries. The European Economic Community (EEC) was created in 1957 between six countries within the Western Bloc and later expanded to twelve countries across Europe. European communist countries had a looser economic grouping with the USSR known as Comecon. To the south there was a non-aligned communist federated country – Yugoslavia. In 1989, the Cold War between the two superpowers was coming to an end, with the USSR's influence over communist Europe collapsing. As the communist states began their transition to free market democracies, aligning to Euro-Atlantic integration, the question of enlargement into the continent was thrust onto the EEC's