(born May 3, 1827, Bideford, Devon, Eng.—died Sept. 15, 1864, Corsham, Wiltshire) British explorer. He was a member of Richard Burton's expedition, and in 1858 Speke and Burton became the first Europeans to reach Lake Tanganyika. On the return trip he left Burton and struck out northward alone. In July 1858 he reached a great lake, which he named Lake Victoria, for the queen. His claim that it was the source of the Nile was questioned, but on a second expedition (1860–63) he found the Nile's exit from the lake. Speke's claim to have found the Nile's source was again challenged in England. He was killed by his own gun while hunting on the very day he was to debate Burton publicly.

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