European integration for greater transparency and trust among themselves. This transfer of national powers to a "Community" to be exercised by its Commission was paralleled under the 1957 Treaty of Rome establishing the European Atomic Energy Community (or Euratom) and the European Economic Community (EEC) in Brussels. In 1967, the Merger Treaty (or Brussels Treaty) combine the institutions of the ECSC and Euratom into that of the EEC. They already shared a Parliamentary Assembly and Courts. Collectively they were known as the European Communities. In 1987, the Single European Act (SEA) was the first major revision of the Treaty of Rome that
History of the European Communities (1958–72) Historical Archives of the European Union in Florence History of the European Communities (1958–72) The history of the European Communities between 1958 and 1972 saw the early development of the European Communities. The European Coal and Steel Community (ECSC) had just been joined by the European Atomic Energy Community (Euratom) and the European Economic Community (EEC), the latter of which soon became the most important. In 1967 the EEC's institutions took over the other two with the EEC's Commission holding its first terms under Hallstein and Rey. In 1958 the Committee of Permanent Representatives (COREPER) was established. On 19 March