Sir Ernest Henry Shackleton was a polar explorer who led three British expeditions to the Antarctic, and one of the principal figures of the period known as the Heroic Age of Antarctic Exploration.
After the race to the South Pole ended in December 1911 with Roald Amundsen's conquest, Shackleton turned his attention to the crossing of Antarctica from sea to sea, via the pole. To this end he made preparations for what became the Imperial Trans-Antarctic Expedition, 1914–17. Disaster struck this expedition when its ship, Endurance, became trapped in pack ice and was slowly crushed before the shore parties could be landed. The crew escaped by camping on the sea ice until it disintegrated, then by launching the lifeboats to reach Elephant Island and ultimately the inhabited island of South Georgia, a stormy ocean voyage of 720 nautical miles and Shackleton's most famous exploit.