offices using Indian Expeditionary Forces stamps (Indian stamps overprinted "I.E.F."). When civilian post offices were opened in 1917, stamps of East Africa and Uganda Protectorates were issued overprinted with "G.E.A.". The same overprint on stamps of East Africa and Uganda Protectorates issued in 1921 after the establishment of Tanganyika are considered part of Tanganyika's postal history. Mafia Island On January 12, 1915, Mafia was taken by British troops as a base for the air and sea assault on the light cruiser Königsberg. Stamps were issued by the British occupation forces on the island of Mafia in 1915 and 1916. See also Postage stamps and postal history of the German colonies Postage stamps and postal history of Ruanda-Urundi Postage stamps and postal history of Rwanda Postage stamps and postal history of Burundi Postage stamps and postal history of Tanganyika Postage stamps and postal history of Tanzania Postage stamps and postal history of Kionga References Economy of German East Africa German East Africa German East Africa German East Africa