sentences:  During World War I (1914–1918), an initial stand-off between the "Force Publique" and the German colonial army in German East Africa (Tanganyika) turned into open warfare with a joint Anglo-Belgian-Portuguese invasion of German colonial territory in 1916 and 1917 during the East African Campaign.The "Force Publique" gained a notable victory when it marched into Tabora in September 1916 under the command of General Charles Tombeur after heavy fighting.After 1918, Belgium was rewarded for the participation of the "Force Publique" in the East African campaign with a League of Nations mandate over the previously German colony of Ruanda-Urundi.