In the wake of Roald Amundsen's 1911 expedition that became the first to successfully reach the South Pole, Sir Ernest Shackleton mounted his Imperial Trans-Antarctic Expedition in 1914, which was tasked with the even more ambitious goal of traveling across the entire Antarctic continent from Vahsel Bay on the coast of the Weddell Sea to McMurdo Sound.

Shackleton had hoped that the sea ice would be relatively loose and passable when he reached it aboard the barquentine Endurance in December 1914, but it turned out to be unexpectedly dense. Despite repeated attempts to push through under steam power, the ship could not make much headway and eventually ended up trapped in the ice so fast that Shackleton feared that the expedition would have to spend the entire Antarctic winter there.

What followed was an incredible story of adventure and survival. Endurance drifted along with the ice for months with its engines extinguished to conserve coal. After moving aimlessly for hundreds of miles, a gale rose in July 1915, breaking up the ice, which now pushed and ground against the ship's hull.

By the end of August, Endurance's timbers were bending like canes and on October 10, 1915, the damage was so severe that Shackleton ordered supplies, tents, and the three lifeboats moved to the ice and the ship abandoned. However, the Blue Ensign was to remain aloft so Endurance could go down flying its colors, which it finally did when the last of its wreckage sank on November 21.

With their ship gone, the 28 men of the Endurance set out on an epic voyage to save themselves. Living on seal and sled dog meat to stretch their rations, they drifted north with the ice until it broke up, then sailed in their open boats to the uninhabited Elephant Island on the tip of the Antarctic peninsula.