The son of Aileen ( Robertson) and
William Slim (later 1st Viscount Slim), he was born in
Quetta in
British India and was educated at
Prince of Wales Royal Indian Military College in
Dehradun. In 1944, Slim joined the
6th Gurkha Rifles of the
British Indian Army and was later transferred to the
Argyll and Sutherland Highlanders in 1948. He entered the
Special Air Service in 1952 in
Malaya, where he was involved in developing pioneering techniques of jungle warfare. He is personally thanked in the author's note at the start of Dennis Holman's 1958 jungle warfare classic, Noone of the Ulu. From 1961, he was instructor at the
Staff College, Camberley, and from 1964 at the
Joint Services Staff College. He commanded an SAS squadron during the
Indonesian Confrontation. In 1967 he became CO of 22 SAS, where he helped to develop its counter-terrorist capabilities, before handing over to
John Watts in 1969. In 1972, he retired from the armed forces at the rank of
lieutenant colonel with a later honorary promotion to
colonel. He was appointed an
Officer of the Order of the British Empire the following year. Slim was chairman of
Peek plc from 1976 to 1991, deputy chairman from 1991 to 1996, and eventually consultant from 1996 to 2003. He was further director of
Trailfinders travel company and Trustee of the
Royal Commonwealth Ex-Services League (RCEL). From 1971 until his death he was president of the
Burma Star Association and from 2000 president of the
SAS Association. He was also Patron of Prospect Burma, a London-based charity that offers higher education scholarships to Burmese students as well as the Graham Layton Trust, a British charity which helps to raise money for eyecare in
Pakistan. From 2005 to 2016 Slim was Patron of the Burma Children's Fund a UK Charity supporting children's education and health care in Burma. Having been chairman in the past, he was vice-president of the
Britain–Australia Society. From 1977 to 1996, he was vice-chairman of the
Arab British Chamber of Commerce. In 1983, Slim was made a Fellow of the
Royal Geographical Society. Between 1995 and 1996, he was also Master of the
Worshipful Company of Clothworkers. He served as an honorary chairman of the
OSS Society. Slim was married to
cordon bleu chef Elisabeth
Spinney from 1958 until her death in 2018. They had two sons,
Mark William Rawdon Slim (born 1960) and
Hugo John Robertson Slim (born 1961), and a daughter, Mary Ann Elisabeth Slim (born 1964). He was appointed as a
Deputy Lieutenant of
Greater London on 1 March 1988. This gave him the
post-nominal letters "DL" for life. He was moved to the
retired list upon reaching the age of 75 in 2002. Slim died on 12 January 2019, aged 91. ==Arms==