Fiennes, Ranulph Twisleton-Wykeham (1944– )

British explorer who made the first surface journey around the world's polar circumference between 1979 and 1982. In 1992 he attempted, with Dr Michael Stroud, the first unsupported crossing of the Antarctic. Though the two men had to be airlifted out before they completed the trip, it was nonetheless the longest unsupported Polar journey ever, recorded in his book Mind Over Matter (1993).

His earlier expeditions included explorations of the White Nile in 1969, Jostedalsbre Glacier, Norway, in 1970, and the Headless Valley, Canada, in 1971. Accounts of his adventures include A Talent for Trouble (1970), Hell on Ice (1979), and the autobiographical Living Dangerously (1987).

Fiennes was born in England but moved to South Africa with his mother after his father died in action in World War II. He returned to England to attend Eton, after which he served for eight years in the British Army. Other expeditions include the discovery of the lost city of Ubar, Oman (1992), and an attempt to travel independently on foot to the North Pole (2000).