Brussels and the European Union a provisional seat, though with the Common Assembly in Strasbourg as that was the only city with a large enough hemicycle (the one used by the Council of Europe). This agreement was temporary, and plans were set to relocate the institutions to Saarbrücken which would serve as a "European District", but this did not occur. The 1957 Treaties of Rome established two new communities, the European Economic Community (EEC) and the European Atomic Energy Community (Euratom). These shared the Assembly and Court of the ECSC but created two new sets of Councils and Commissions (equivalent to the ECSC's High Authority).
Three pillars of the European Union Euratom) whose organisational structure had already been unified in 1965-67, through the Merger Treaty. Later, through the Treaty of Maastricht the word "Economic" was removed from the EEC, so it became simply the EC. Then with the Treaty of Amsterdam additional areas would be transferred from the third pillar to the first. In 2002, the ECSC (which had a lifetime of 50 years) ceased to exist because the treaty which established it, the Treaty of Paris, had expired. In the CFSP and PJCCM pillars the powers of the European Parliament, the Commission and European Court of Justice with respect to