In January 1866, Livingstone returned to Africa, this time to Zanzibar, and from there he set out to seek the source of the Nile. Richard Francis Burton, John Hanning Speke, and Samuel Baker had identified either Lake Albert or Lake Victoria as the source (which was partially correct, as the Nile "bubbles from the ground high in the mountains of Burundi halfway between Lake Tanganyika and Lake Victoria"), but there was still serious debate on the matter. Livingstone believed that the source was farther south and assembled a team to find it consisting of freed slaves, Comoros Islanders, twelve Sepoys, and two servants from his previous expedition, Chuma and Susi.