A dispute over the terms for the granting of full sovereignty to the self @-@ governing colony of Rhodesia ( or Southern Rhodesia ) led the colonial government , headed by Prime Minister Ian Smith , to unilaterally declare independence from the United Kingdom on 11 November 1965 . The idea of " no independence before majority rule " had recently gained ground in Britain and elsewhere amid decolonisation , and Rhodesia 's government was dominated by the country 's white minority , so the unilateral declaration went unrecognised internationally . Britain and the United Nations imposed economic sanctions on Rhodesia .