British explorer Richard Burton set out to Africa in 1858 to discover what?

For centuries, the origin of the world's longest river was one of the greatest geographical mysteries on Earth. In the mid-19th century, solving it became an obsession for European explorers. The renowned adventurer and linguist Sir Richard Burton, sponsored by the Royal Geographical Society, embarked on an ambitious expedition with his colleague John Hanning Speke to finally locate the headwaters of the great (Review) river and claim the prestigious prize.

Their journey into the African interior was grueling, marked by debilitating tropical diseases that afflicted both men. Near the end of their trek, Burton became too ill to continue, forced to recuperate in a camp. Speke, recovering more quickly, pushed on alone and came across a massive inland sea, which he named Lake Victoria. He was immediately convinced that this vast body of water was the long-sought-after source.

Burton, however, was deeply skeptical of Speke's unproven theory. Upon their return to England, their disagreement erupted into a bitter and public feud. While Speke was ultimately proven to be largely correct, it was his solitary discovery that solved the ancient riddle. Because Burton fell ill and fiercely disputed the finding, his own famous expedition is remembered as a personal failure in achieving its primary goal.