European Economic Community Duchesse conference centre in 1956. Together with the Ohlin Report the Spaak Report would provide the basis for the Treaty of Rome. In 1956, Paul Henri Spaak led the Intergovernmental Conference on the Common Market and Euratom at the Val Duchesse conference centre, which prepared for the Treaty of Rome in 1957. The conference led to the signature, on 25 March 1957, of the Treaty of Rome establishing a European Economic Community. The resulting communities were the European Economic Community (EEC) and the European Atomic Energy Community (EURATOM or sometimes EAEC). These were markedly less supranational than the previous communities,
European Coal and Steel Community their fields rapidly expanded and the EEC became the most important tool for political unification, overshadowing the ECSC. Despite being separate legal entities, the ECSC, EEC and Euratom initially shared the Common Assembly and the European Court of Justice, although the Councils and the High Authority/Commissions remained separate. To avoid duplication, the Merger Treaty merged these separate bodies of the ECSC and Euratom with the EEC. The EEC later became one of the three pillars of the present day European Union. The Treaty of Paris was frequently amended as the EC and EU evolved and expanded. With the treaty due