Fiennes was born in Windsor, Berkshire, on 7 March 1944, nearly four months after the death of his father, Lieutenant-Colonel Sir Ranulph Twisleton-Wykeham-Fiennes.

[2] Whilst commanding the Royal Scots Greys in Italy Fiennes' father trod on a German anti-personnel S-mine and died of his wounds eleven days later in Naples on 24 November 1943.

After failing to gain entry into the Royal Military Academy Sandhurst, Fiennes attended Mons Officer Cadet School.

[6] After completing several months' training, on 27 July 1963 he was granted a short service commission in his late father's former regiment, the Royal Scots Greys.

A notable trek was the Transglobe Expedition he undertook between 1979 and 1982, when he and two fellow members of 21 SAS, Oliver Shepard and Charles R. Burton, journeyed around the world on its polar axis, using surface transport only.

A further attempt in 1996 to walk to the South Pole solo, in aid of the Breast Cancer Campaign, was unsuccessful due to a kidney stone attack and he had to be rescued from the operation by his crew.

On returning home, his surgeon insisted the necrotic fingertips be retained for several months before amputation, to allow regrowth of the remaining healthy tissue.

However, bad weather and aeroplane engine trouble caused him to change his plans, running the South American segment in southern Patagonia first and then hopping to the Falklands as a substitute for the Antarctic leg.

In March 2007, despite a lifelong fear of heights, Fiennes climbed the Eiger by its North Face, with sponsorship totalling £1.8 million to be paid to the Marie Curie Cancer Care Delivering Choice Programme.

[20] Of the other handful of adventurers who had visited both poles, only four had successfully crossed both polar icecaps: Norwegian Børge Ousland, Belgian Alain Hubert and Fiennes.

[21] Fiennes continues to compete in UK-based endurance events and has seen recent success in the veteran categories of some Mountain Marathon races.

[citation needed] In September 2012 it was announced that Fiennes was to lead the first attempt to cross Antarctica during the southern winter, in aid of the charity Seeing is Believing, an initiative to prevent avoidable blindness.

The six-man team was dropped off by ship at Crown Bay in Queen Maud Land in January 2013, and waited until the Southern Hemisphere's autumnal equinox on 21 March 2013 before embarking across the ice shelf.

The intention was for Fiennes and his skiing partner, Dr Mike Stroud,[22] to lead on foot and be followed by two bulldozers dragging industrial sledges.

[28] In August 2014, Fiennes was one of 200 public figures who were signatories to a letter to The Guardian opposing Scottish independence in the run-up to September's referendum on that issue.

[29] As a guest on the British motoring television programme Top Gear, as a Star in a Reasonably Priced Car, his test track lap time, in a Suzuki Liana was 1:51, putting him 26th out of 65.

According to an interview on Top Gear, Fiennes was considered for the role of James Bond during the casting process, making it to the final six contenders, but was rejected by Cubby Broccoli for having "hands too big and a face like a farmer", and Roger Moore was eventually chosen.

[31] Between 1 and 5 October 2012, and again from 13 to 19 November 2013, Fiennes featured on the Channel 4 game show Countdown as the celebrity guest in 'Dictionary Corner' and provided interludes based on his life stories and explorations.

[34] Fiennes embarked on a lecture tour, where in Cheshire he met Louise Millington, whom he married at St Boniface's Church, Bunbury, one year and three weeks after Ginny's death.

[36] In 2003, shortly after boarding a flight to Scotland from Bristol Airport, Fiennes suffered a heart attack and later underwent emergency bypass surgery.

[37] Fiennes is a member of the Worshipful Company of Vintners and the Highland Society of London and holds honorary membership of the Travellers Club.

[40] Fiennes was appointed Officer of the Order of the British Empire in 1993 for "human endeavour and for charitable services":[41] in 2015 it was reported his expeditions have raised £16 million for good causes.

In the other two episodes they undertook a voyage around Cape Horn and an expedition hauling sledges across the deep-frozen Frobisher Bay in the far north of Canada.

[50] In October 2014 it was announced that Fiennes would receive an honorary Doctorate of Science, from the University of Chester, in recognition of "outstanding and inspirational contribution to the field of exploration".