Belgium felt he had collaborated with Germany during the war. The Belgian Congo gained independence in 1960 during the Congo Crisis; Ruanda-Urundi followed with its independence two years later. Belgium joined NATO as a founding member and formed the Benelux group of nations with the Netherlands and Luxembourg. Belgium became one of the six founding members of the European Coal and Steel Community in 1951 and of the European Atomic Energy Community and European Economic Community, established in 1957. The latter has now become the European Union, for which Belgium hosts major administrations and institutions, including the European Commission, the Council
Partitions of Luxembourg of Luxembourg would be decided later; the Netherlands, which had assented to the Conference's decision, invaded Belgium to force the Belgians to accept limitation of its territory. After the withdrawal of this force, the London Conference made its third suggestion, that Luxembourg be divided between the two, with most of the land going to Belgium, but with Luxembourg City remaining under Dutch control. Leopold agreed, and the treaty was signed on the 15 November 1831. Although the Dutch King William I rejected this suggestion at first, after the stand-off had dragged on for several years, he gave way, and agreed