They were members of the imperial trans-south pole expedition, with the aim of making the first crossing of the Antarctic continent.
But after the three-master Endurance got stuck in the ice and was finally crushed after 10 months, Shackleton and his 27-man crew went north in lifeboats, cruising over water and trailing ice floes.
They reached Elephant Island, at the tip of the Antarctic Peninsula, where Shackleton left most of the crew.
He left them to maintain penguins and to seal flesh. Then he left with five others, in a small boat, to reach the island of South Georgia, 800 miles away.
It was remarkable that they had made it, but then had to drag themselves over a series of mountains to reach a whaling station on the other side of the island.
After regaining his strength, Shackleton succeeded in saving the rest of his crew from Elephant Island. Not one man died.
Shackleton embarked on a new Antarctic expedition in 1921, but died at the beginning of the trip to South Georgia.