The Emin Pasha Relief Expedition of 1886 to 1889 was one of the last major European expeditions into the interior of Africa in the nineteenth century, ostensibly to the relief of Emin Pasha, General Charles Gordon's besieged governor of Equatoria, threatened by Mahdist forces. The expedition was led by Henry Morton Stanley and came to be both celebrated for its ambition in crossing "darkest Africa", and notorious for the deaths of so many of its members and the disease unwittingly left in its wake.
The Mahdists captured Khartoum in 1885 and Egyptian administration of the Sudan collapsed, and the extreme southern province Equatoria was nearly cut off from the outside world, located as it was on the upper reaches of the Nile near Lake Albert. Emin Pasha was an Ottoman doctor and naturalist who had been appointed Governor of Equatoria. He was able to send and receive letters via Buganda and Zanzibar and had been informed in February 1886 that the Egyptian government would abandon Equatoria. In July, he was encouraged by missionary Alexander Mackay to invite the British government to annex Equatoria itself. The government was not interested in such a doubtful venture, but the British public came to see Emin as a second General Gordon in mortal danger from the Mahdists.
Scottish businessman and philanthropist William Mackinnon had been involved in various colonial ventures, and by November he had approached Stanley about leading a relief expedition. Stanley declared himself ready "at a moment's notice" to go. Mackinnon then approached J. F. Hutton, a business acquaintance also involved in colonial activities, and together they organized the "Emin Pasha Relief Committee", mostly consisting of Mackinnon's friends, whose first meeting was on 19 December 1886. The Committee raised a total of about £32,000.