stern Front fighting of World War I occurred in western parts of the country. The opening months of the war were known as the Rape of Belgium due to German excesses. Belgium took over the German colonies of Ruanda-Urundi (modern day Rwanda and Burundi) during the war, and they were mandated to Belgium in 1924 by the League of Nations. In the aftermath of the First World War, the Prussian districts of Eupen and Malmedy were annexed by Belgium in 1925, thereby causing the presence of a German-speaking minority.
The country was again invaded by Germany in 1940 and was occupied until its liberation by the Allies in 1944. After World War II, a general strike forced king Leopold III, who many viewed as collaborating with Germany during the war, to abdicate in 1951. 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 is now the European Union, for which Belgium hosts major administrations and institutions, including the European Commission, the Council of the European Union and the extraordinary and committee sessions of the European Parliament
