History of the European Union Europe Declaration (1951). This principle was at the heart of the European Coal and Steel Community (ECSC) (1951), the Treaty of Paris (1951), and later the Treaty of Rome (1958) which established the European Economic Community (EEC) and the European Atomic Energy Community (EAEC). Both the ECSC and EEC were later incorporated into the European Union while the EAEC maintains a distinct legal identity despite sharing members and institutions. The Maastricht Treaty (1992) created the European Union with its pillars system, including foreign and home affairs alongside the European Community. This in turn led to the creation of the single
European Economic Community Community", continuing to follow the supranational structure of the EEC. The EEC institutions became those of the EU, however the Court, Parliament and Commission had only limited input in the new pillars, as they worked on a more intergovernmental system than the European Communities. This was reflected in the names of the institutions, the Council was formally the "Council of the "European Union"" while the Commission was formally the "Commission of the "European Communities"". However, after the Treaty of Maastricht, Parliament gained a much bigger role. Maastricht brought in the codecision procedure, which gave it equal legislative power with the