The mouth of the Congo River was visited (1482) by Diogo Cão, the Portuguese navigator. It became known as the Zaïre River (a corruption of the local name Mzadi meaning "great water") and was later referred to as the Congo River (for the Kongo kingdom located near its mouth); it was called Zaïre River by the government of Zaïre (now Congo [Kinshasa]) from 1971 to 1997. The Congo's lower course was traced upstream as far as Isangila by a British force under Capt. J. K. Tuckey in 1816, and its upper headwaters by the missionary David Livingstone, who followed the Lualaba River to Nyangwe in 1871. The journalist Henry Stanley traveled from Nyangwe to Isangila and on to Boma during his great transcontinental journey (1874–77), thus proving the headwaters to be tributaries of the Congo River, and not sources of the Nile as hypothesized by Livingstone.