 Following World War I , Belgium possessed two colonies in Africa — the Belgian Congo , which it had controlled since its annexation of the Congo Free State in 1908 , and Ruanda @-@ Urundi , a former German colony that had been mandated to Belgium in 1924 by the League of Nations . The Belgian colonial military numbered 18 @,@ 000 soldiers , making it one of the largest standing colonial armies in Africa at the time . 
