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
Three pillars of the European Union Three pillars of the European Union Between 1993 and 2009, the European Union (EU) legally comprised three pillars. This structure was introduced with the Treaty of Maastricht on 1 November 1993, and was eventually abandoned on 1 December 2009 upon the entry into force of the Treaty of Lisbon, when the EU obtained a consolidated legal personality. Within each pillar, a different balance was struck between the supranational and intergovernmental principles. Supranationalism was strongest in the first pillar. Its function generally corresponded at first to the three European Communities (European Coal and Steel Community (ECSC), European Economic Community (EEC) and