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 due to protests from some countries that their sovereignty was being infringed (however there would still be concerns with the behaviour of the Hallstein Commission). The first formal meeting of the Hallstein Commission was held on 16 January 1958 at the Chateau de Val-Duchesse. The EEC (direct ancestor of the modern Community) was to create a customs union while Euratom would promote co-operation in the nuclear power sphere. The EEC rapidly became the most important of these and expanded its activities. One of the first important accomplishments of the EEC was the establishment (1962) of common price levels for agricultural