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).
2004 enlargement of the European Union countries. The European Economic Community (EEC) was created in 1957 between six countries within the Western Bloc and later expanded to twelve countries across Europe. European communist countries had a looser economic grouping with the USSR known as Comecon. To the south there was a non-aligned communist federated country – Yugoslavia. In 1989, the Cold War between the two superpowers was coming to an end, with the USSR's influence over communist Europe collapsing. As the communist states began their transition to free market democracies, aligning to Euro-Atlantic integration, the question of enlargement into the continent was thrust onto the EEC's