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 Coal and Steel Community their fields rapidly expanded and the EEC became the most important tool for political unification, overshadowing the ECSC. Despite being separate legal entities, the ECSC, EEC and Euratom initially shared the Common Assembly and the European Court of Justice, although the Councils and the High Authority/Commissions remained separate. To avoid duplication, the Merger Treaty merged these separate bodies of the ECSC and Euratom with the EEC. The EEC later became one of the three pillars of the present day European Union. The Treaty of Paris was frequently amended as the EC and EU evolved and expanded. With the treaty due