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
Accession of the United Kingdom to the European Communities Accession of the United Kingdom to the European Communities The Accession of the United Kingdom to the European Communities (EC) – the collective term for the European Coal and Steel Community (ECSC), the European Economic Community (EEC) and the European Atomic Energy Community (EAEC) – took effect on 1 January 1973. This followed ratification of the Accession treaty which was signed in Brussels on 22 January 1972 by the Conservative prime minister Edward Heath, who had pursued the UK's application to the EEC since the late 1950s. Denmark and Ireland also joined as part of the same expansion but Norway,