British adventurer Sir Ranulph Fiennes has battled against blizzards and mechanical problems to complete the first leg of his seven continents, seven marathons challenge.
The pair have already had to abandon one planned run
Poor weather and engine trouble forced Sir Ranulph and his running partner Dr Michael Stroud to abandon plans to fly to King George Island in Antarctica to start their seven-day challenge.
Instead they began their first marathon alongside the wild waters of the Magellan Strait in Patagonia, southern Chile, completing it in under four hours.
Sir Ranulph, 59, who recently underwent a double heart bypass operation, praised his running partner, saying: "Mike is always fantastic. He gets the pace exactly right."
They next plan to head to the Falkland Islands, which will be deemed to fulfil the Antarctic leg.
Sir Ranulph told the Times: "I'm obviously not looking forward to phoning our Santiago organisers [where the second run had been scheduled to take place] and telling them the whole thing's off, but I'm relieved to be running at last."
The challenge will also take the pair to Sydney, Singapore, London, Cairo, and New York covering 183 miles of marathons and 45,000 miles of air travel.
Sir Ranulph will run the 26-mile London leg of the challenge on the morning of 31 October before jetting to Africa to begin his second marathon in a day just before midnight in Cairo.
He will finish the challenge with the official New York marathon on 2 November.
The 59-year-old who lives in Exmoor, had already promised to take on the Land Rover 7x7x7 Challenge before he collapsed in June and had to undergo an emergency double heart bypass operation at the Bristol Royal Infirmary.
All money raised from the marathons will be given to the British Heart Foundation.