Germany invaded Belgium in August 1914 as part of the Schlieffen Plan to attack France, and much of the Western 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 assumed control of the German colonies of Ruanda-Urundi (modern-day Rwanda and Burundi) during the war, and in 1924 the League of Nations mandated them to Belgium. In the aftermath of the First World War, Belgium annexed the Prussian districts of Eupen and Malmedy in 1925, thereby causing the presence of a German-speaking minority.