He was brought up in South Africa where he remained until the age of 12 when he returned to England to be educated at Eton, after which he joined the British Army.

Fiennes served for eight years in his father's regiment, the Royal Scots Greys, and was later seconded to the Special Air Service. He went on to join the army of the Sultan of Oman where he received the country’s Bravery Medal in 1971.

Sir Ranulph married his childhood sweetheart, Virginia Pepper (Ginny), in 1970 and together they launched a series of record breaking expeditions that kept them ahead of their international rivals for three decades. Ginny died of cancer in 2004. In March 2005, he was married for a second time to Louise Millington; they honeymooned at Everest Base Camp. They have a daughter, Elizabeth.

Fiennes was the first man to reach both poles by surface travel and the first to cross the Antarctic Continent unsupported.

He has led over 30 expeditions including the first polar circumnavigation of the Earth, and in 2003 he ran seven marathons in seven days on seven continents.

Sir Ranulph has raised over £13 million to date for various UK charities including Marie Curie Cancer Care for whom he has raised £5.6 million after successfully climbing the North Face of the Eiger in March 2007, and attempting to climb Everest (Nepal-side) to within 400m from the summit in May 2008.

In 1993 he was awarded the Order of the British Empire (OBE) for ‘human endeavour and charitable services’. According to the Guinness Book of World Records he is the ‘greatest living explorer’ and was also named Best Sportsman in the 2007 Great Briton Awards.

Sir Ranulph hopes to join Richard for the last leg of his challenge. This will be confirmed nearer the time.