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).
Maastricht Treaty of the obligations of the treaty for the members was to keep "sound fiscal policies, with debt limited to 60% of GDP and annual deficits no greater than 3% of GDP". The treaty also created what was commonly referred to as the pillar structure of the European Union. The treaty established the three pillars of the European Union—one supranational pillar created from three European Communities (which included the European Economic Community (EEC), the European Coal and Steel Community and the European Atomic Energy Community), the Common Foreign and Security Policy (CFSP) pillar, and the Justice and Home Affairs (JHA) pillar.