David Livingstone was a Scottish Congregationalist pioneer medical missionary with the London Missionary Society and an explorer in Africa, one of the most popular national heroes of the late-19th-century in Victorian Britain. He had a mythical status that operated on a number of interconnected levels: Protestant missionary martyr, working-class "rags-to-riches" inspirational story, scientific investigator and explorer, imperial reformer, anti-slavery crusader, and advocate of commercial and colonial expansion. His fame as an explorer and his obsession with discovering the sources of the River Nile was founded on the belief that if he could solve that age-old mystery, his fame would give him the influence to end the East African Arab-Swahili slave trade. "The Nile sources," he told a friend, "are valuable only as a means of opening my mouth with power among men. It is this power which I hope to remedy an immense evil." His subsequent exploration of the central African watershed was the culmination of the classic period of European geographical discovery and colonial penetration. At the same time, his missionary travels, "disappearance", and eventual death in Africa—​​and subsequent glorification as a posthumous national hero in 1874—​​led to the founding of several major central African Christian missionary initiatives carried forward in the era of the European "Scramble for Africa". His meeting with Henry Morton Stanley on 10 November 1871 gave rise to the popular quotation "Dr. Livingstone, I presume?"

https://en.wikipedia.org/wiki/David_Livingstone