Fridtjof Nansen was a 12-time Norwegian cross-country ski champion who refined his technique by studying Telemark skiers. After a sealing voyage to the Arctic in 1882, where his ship was trapped in ice off Greenland, he took a post at the Bergen Museum, sliced hagfish spinal cords, and became one of the first scientists to defend the neuron doctrine against Camillo Golgi’s reticular theory. He then crossed Greenland’s ice cap from the empty east coast toward the settled west, so retreat was impossible. His six-man party climbed to nearly 9,000 feet in temperatures of minus 49 degrees Fahrenheit, proved the interior was a continuous ice dome, and rowed down a fjord in a boat built from sledges and willow.

Wreckage of the Jeannette, crushed off Siberia, had washed up near Greenland, so Nansen reasoned a current crossed the polar sea. Colin Archer built the Fram with a rounded hull that ice would squeeze upward, and in 1893 she froze in off Siberia and drifted. When the drift would miss the pole, Nansen and Hjalmar Johansen set out by dog sled and reached a record 86 degrees 14 minutes. Their chronometers stopped, and they wintered eight months in a stone and moss hut on Franz Josef Land, living on walrus and polar bear, until Nansen heard a dog bark and met British explorer Frederick Jackson. The Fram returned weeks after them without losing a man.

• In 1905 he won British support for Norway’s peaceful separation from Sweden and negotiated with a Danish prince to become its king.
• For the League of Nations he repatriated more than 400,000 prisoners of war, dealing directly with the Soviets.
• He ran a private relief campaign with the Red Cross during the 1921 Russian famine that threatened 30 million people.
• His Nansen passport gave stateless refugees identity papers recognized by more than 50 governments.
• He won the 1922 Nobel Peace Prize, gave the money to relief work, and advocated for Armenian refugees until his death in 1930.