When on 21st November 1915 the polar explorer ship Endurance finally yielded to the Antarctic pack ice, Ernest Shackleton and his crew began one of the most gruelling survival attempts in history.

Their five-month ordeal on the ice floes followed by the all-or-nothing 720-nautical-mile dash to South Georgia has since become the stuff of legend, pored over by scholars and adventurers for more than a century.

But of the ship itself, no trace has been detected since the day it went down.

On Monday, a British-led team announced it was setting out to find the wreck of Endurance, thought to be at rest nearly two miles beneath the Larsen C Ice Shelf in the Weddell Sea.

Operating from the research vessel SA Agulhas II, the expedition will use the most advanced unmanned submarines in the world to scour the sea bed.