In March 1861 he started upon his first tour of exploration in central Africa. This, in his own words, was undertaken "to discover the sources of the river Nile, with the hope of meeting the East African expedition under Captains
Speke and
Grant somewhere about the
Lake Victoria." After a year spent on the
Sudan–Ethiopian frontier, during which time he learned
Arabic, explored the
Atbara river and other Nile tributaries, and proved that the Nile sediment came from Ethiopia, he arrived at
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 being led by the local Africans to 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 first European visit to 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 1864. After some time spent in the exploration of the neighbourhood, Baker demonstrated that the Nile flowed through the Albert Nyanza. He formed an exaggerated idea of the relative importance of the Albert and Victoria lake sources in contributing to the Nile flow rate. Although he believed them to be near equal, Albert Nyanza sources add only ~15% to the Nile flow at this point, the remainder provided primarily by outflow from Lake Victoria. While in this area, Baker and his wife became the first Europeans to see a substantial waterfall on the Victoria Nile, which Baker named
Murchison Falls after the then-president of the
Royal Geographical Society,
Sir Roderick Murchison. He started upon his return journey, and reached Khartoum, after many checks, in May 1865. In the following October Baker returned to England with his wife, who had accompanied him throughout the dangerous and difficult journeys in Africa. In recognition of the achievements, the Royal Geographical Society awarded him its
Patron's Medal, and a similar distinction was bestowed on him by the
Paris Geographical Society. In August 1866 he was knighted. In the same year he published ''The Albert N'yanza, Great Basin of the Nile, and Explorations of the Nile Sources
, and in 1867 The Nile Tributaries of Abyssinia
, both books quickly turned into several editions. In 1868 he published a popular story called Cast up by the Sea''. In 1869 he travelled with the future
King Edward VII (who was the Prince of Wales at that time) through Egypt. Baker never received quite the same level of acclamation granted to other contemporary British explorers of Africa. Queen Victoria, in particular, avoided meeting Baker because of the irregular way in which he acquired Florence, not to mention the fact that during the years of their mutual travels, the couple were not actually married. A court case involving his brother
Valentine Baker (following his indecent assault of a woman on a train) also harmed Baker's chances of wider acceptance by the Victorian establishment. In 1869, at the request of the
khedive Ismail, Baker led a military expedition to the equatorial regions of the Nile, with the object of suppressing the
slave-trade there and opening the way to commerce and civilisation. Before starting from Cairo with a force of 1700 Egyptian troops – many of them discharged convicts – he was given the rank of
pasha and major-general in the
Ottoman army. Lady Baker, as before, accompanied him. The khedive appointed him
Governor-General of the new territory of
Equatoria for four years at a salary of £10,000 a year; and it was not until the expiration of that time that Baker returned to Cairo, leaving his work to be carried on by the new governor, Colonel
Charles George Gordon. He had to contend with innumerable difficulties – the blocking of the river in the
Sudd, the hostility of officials interested in the slave-trade, the armed opposition of the natives – but he succeeded in planting in the new territory the foundations upon which others could build up an administration. ==Later life==