Though weakened by starvation, frostbite, injury and smashed equipment, Sir Ranulph, 49, and Dr Stroud, 37, still managed to make 27 miles down the Beardmore Glacier.
Even in the spiteful and quarrelsome world of polar exploration, this has a good chance of being recorded as the first-ever unsupported Antarctic traverse.
The two men, who set off from Gould Bay on the Weddell Sea on 9 November, have been beset by delay, an unhappy choice of route, crevasses, short rations, the loss of auxiliary radio equipment and public indifference.
For the first leg of the journey, they were in the shadow of Erling Kagge, the Norwegian skier who accomplished the journey to the Pole, solo, without support.
But late last week, the expedition began to reveal the scale of the men's suffering over the last 89 days in their attempt to raise money for the Multiple Sclerosis Society. Sir Ranulph has a badly inflamed and frostbitten foot and Dr Stroud has frostbitten hands. They have both lost more than a quarter of their bodyweight. They have skied at least 1,257 miles.
According to Mr Laurence Howell, one of the expedition's UK supporters, this outdoes the longest ever made in polar latitudes, in 1908/09, when three members of Sir Ernest Shackleton's expedition travelled 1,245 miles to the magnetic South Pole.