The famed British explorer who disappeared in Africa while seeking the source of the Nile was Dr. David Livingstone. He was a Scottish missionary and explorer known for his extensive travels across Africa in the 19th century. Livingstone's expeditions aimed to promote Christianity and seek out the source of the Nile River, which was a subject of great intrigue at the time. In 1866, he ventured into the African interior but lost contact with the outside world for several years, leading to concerns for his safety. He was eventually found by journalist Henry Morton Stanley in 1871, famously greeting him with, "Dr. Livingstone, I presume?"