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
European Economic Community the European Union, though limited in some areas due to the pillar structure. Despite this, Parliament in particular has gained more power over legislation and security of the Commission. The Court was the highest authority in the law, settling legal disputes in the Community, while the Auditors had no power but to investigate. The EEC inherited some of the Institutions of the ECSC in that the Common Assembly and Court of Justice of the ECSC had their authority extended to the EEC and Euratom in the same role. However the EEC, and Euratom, had different executive bodies to the ECSC.