Henry Morton Stanley the source of the Nile. Between 1875 and 1876 Stanley succeeded in the first part of his objective, establishing that Lake Victoria had only a single outlet – the one located by John Hanning Speke on 21 July 1862. If this was not the Nile's source, then the massive northward flowing river called by Livingstone, the Lualaba, and mapped by him in its upper reaches, might flow on north to connect with the Nile via Lake Albert and thus be the primary source. It was therefore essential that Stanley should trace the course of the Lualaba downstream (northward) from Nyangwe,
Sidi Mubarak Bombay slave in India many years and learned Hindi. He was emancipated after his owner died, and returned to Africa. In Africa, Bombay met John Hanning Speke, who asked him to join his expedition to find the source of the Nile River. Bombay and Speke communicated with each other in Hindi, as it was the only language both of them understood. Bombay was well regarded by the British explorers; in the words of Burton, "The gem of the party, however, is one Sidi Mubarak, who has taken to himself the agnomen of 'Bombay.'" Between 1856 and 1876, Bombay participated in expeditions