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).
European Economic Community Community", continuing to follow the supranational structure of the EEC. The EEC institutions became those of the EU, however the Court, Parliament and Commission had only limited input in the new pillars, as they worked on a more intergovernmental system than the European Communities. This was reflected in the names of the institutions, the Council was formally the "Council of the "European Union"" while the Commission was formally the "Commission of the "European Communities"". However, after the Treaty of Maastricht, Parliament gained a much bigger role. Maastricht brought in the codecision procedure, which gave it equal legislative power with the