John Hanning Speke arrange a better relationship for Mere with another man, without success it seems. Finally, given permission by Mutesa in June 1862 to leave, Speke then travelled down the Nile now reunited with Grant. Because of travel restrictions placed by the local chieftains, slave raiding parties, tribal wars and the difficulty of the terrain, Speke was not able to map the entire flow of the Nile from Lake Victoria north. Why he did not make more efforts to do so is not clear, but the enormous hardships of the journey must have played a large role. By January 1863 Speke and
Congo-Nile Divide northwest provided the easiest route. The Ruzizi River, flowing south into Lake Tanganyika, is part of the upper watershed of the Congo River. Nineteenth-century British explorers such as Richard Francis Burton and John Hanning Speke, uncertain of the direction of flow of the Ruzizi, thought that it might flow north out of the lake toward the White Nile. Their research and follow-up explorations by David Livingstone and Henry Morton Stanley established among Europeans that this was not the case. The Ruzizi flows into Lake Tanganyika, which overflows into the Lukuga River about south of Ujiji. The Lukuga flows west into