Tanganyika is the name of an East African territory (an, from December 9, 1961 to April 26, 1964, an independent nation) lying between the largest of the African great lakes: Lake Victoria, Lake Malawi and Lake Tanganyika, after which it was named. Once part of the colony of German East Africa (German: Deutsch-Ostafrika), it comprises the mainland part of today's Tanzania, which includes the islands of Zanzibar. After World War I it came under British military rule and its transfer to Britain under the 1919 Treaty of Versailles was confirmed by a League of Nations Mandate in 1922, later a United Nations Trust Territory. Britain changed the name to the Tanganyika Territory.