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,
Samuel Baker Khartoum, leaving that city in December 1862 to follow up the course of the White Nile. Two months later at Gondokoro he met Speke and Grant, who, after discovering the source of the Nile, were following the river to Egypt. Their success made him fear that there was nothing left for his own expedition to accomplish; but the two explorers gave him information which enabled him, after separating from them, to achieve the discovery of Albert Nyanza (Lake Albert), of whose existence credible assurance had already been given to Speke and Grant. Baker first sighted the lake on 14 March