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 the ECSC and Euratom were merged with that of the EEC, creating a single institutional structure governing the three separate Communities. From here on, the term "European Communities" were used for the institutions (for example, from "Commission of the European Economic Community" to the "Commission of the European Communities"). The Council of the European Communities was a body holding legislative and executive powers and was thus the main decision making body of the Community. Its Presidency rotated between the member states every six months and it is related to the European Council, which was an informal gathering of national leaders