text: when did tanganyika get its independence?   december 9, 1961  tanganyika was an east african republic within the commonwealth of nations, named after lake tanganyika, which formed its western border. in 1964, it united with the island of zanzibar to form tanzania.  the name first appeared as the mandated territory of tanganyika, which was formed from the colony of german east africa, awarded to the british following world war i by mandate in 1922 by the league of nations. in 1946 it became a trust territory of the united nations, still ruled by the british, and finally gaining independence on december 9, 1961. the "republic of tanganyika" was established a year later, june 9, 1962.