During the First World War, the East African Campaign greatly affected the African Great Lakes region. The allied powers, the British Empire and Belgium launched a coordinated attack on the German colony. The German army stationed in Burundi was forced to retreat by the numerical superiority of the Belgian army and by 17 June 1916, Burundi and Rwanda were occupied. The Force Publique and the British Lake Force then started a thrust to capture Tabora, an administrative centre of central German East Africa. After the war, as outlined in the Treaty of Versailles, Germany was forced to cede "control" of the Western section of the former German East Africa to Belgium.