Member of the Marks and Spencer family - Sieff was the great-grandson of Michael Marks - and Jonathan remained in the business world until his retirement. The Sieff's - another great-grandfather Eprahim came over from Lithuania to avoid Russian military service - were also involved in assisting the creation of the State of Israel. Jonathan's daughter married the son of Baron Howard of Henderskelfe, the former Chairman of the Governors at the BBC. A car enthusiast all his life, especially enjoying maintaining motor vehicles in the Royal Army Ordnance Corps on Dartmoor, Sieff also raced, being a regular in sports cars between 1956 and 1959 and in 1960, with Michael Taylor, set up the Taylor and Crawley Racing team with both men to attempt an ex-Innes Ireland Lotus 18. However the team pretty much stopped before it started after Taylor had a horrific crash at the Belgian Grand Prix in which he was lucky to survive. Jonathan then was badly hurt in a Le Mans crash, with head injuries and multiple fractures, of which he, too, was lucky to survive. Between 1965 (after Charles Cooper's death) and 1969, he ran the Cooper team, investing into it from his role in the Chipstead Motor Group. He largely left the sport after that and concentrated on horse riding. However, he was still a visitor to historic events. He was a director of financial firm for many years and then served as a director of an investment firm. A man of numerous interests, including music, books, art, cooking, shooting and Shakespeare, Jonathan died in 2020 after suffering a stroke.

Biography last updated 3 Aug 2020