Sir Ernest Shackleton
Expedition Leader

An Irish-born polar expedition veteran, Shackleton approached to within 745 miles of the South Pole with Robert Scott on the 1901 Discovery expedition, then pressed to within 97 miles on his own Nimrod expedition of 1908. Imperious, single-minded, ferociously loyal to his men, he once said "Optimism is true moral courage," a tenet he lived by until his death on South Georgia Island in 1922.