President of the European Commission three executives that were merged in 1967 following the Merger Treaty, namely the High Authority of the European Coal and Steel Community (from 1952), and the commissions of the European Atomic Energy Community and the European Economic Community (both from 1958). Secondly, a list is given over the presidents after the merger, when the single position presided over the Commission of the European Communities, until 2009 when the Treaty of Lisbon renamed of the institution, creating the President of the European Commission. The European Economic Community was established by the Treaty of Rome, presently known as the Treaty on the
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