Brian Field (15 December 1934 – 27 April 1979) was a solicitor's clerk who was one of the masterminds of the Great Train Robbery. He was the crucial link between the key informant known only as "Ulsterman" (who came up with the idea of robbing the money-laden night mail train and also provided the details of the schedule and contents of the trains) with the actual gang capable of planning and carrying out such a complex and large scale robbery. He was found guilty of "Conspiracy to Rob" but this was later overturned on appeal. Field only served jail time for "Obstruction of Justice" in relation to arranging the purchase of Leatherslade Farm, which was used as the gang's hideout.
Field was born on 15 December 1934 at Windsor and was immediately put up for adoption.
He served two years in the Royal Army Service Corps, seeing service in Korea. When discharged from the military it was with 'a very good character'. The Korean War lasted from 25 June 1950 until an Armistice was signed on 27 July 1953, with 63,000 British troops involved (part of over 1 million troops on the South Korean side). Field would have been 18 when the war was over. While the Service Corps were considered combat personnel, they were primarily associated with transport and logistics.
Brian Field quickly became successful in both his personal and professional lives, he married a pretty German girl Karin and rose to be a solicitor's managing clerk for John Wheater & Co. Despite the fact that he was only 28 at the time of the robbery, he was already much more successful than his boss, John Wheater. Field drove a new Jaguar and had a house he called "Kabri" (an amalgam of Karin and Brian) with his wife at the Bridle Path, Whitchurch Hill, Oxfordshire, near Pangbourne, while his boss owned a battered Ford and lived in a rundown neighbourhood. Part of the reason for this is that Field was not averse to giving some of his less savoury clients good information on what some of his wealthier clients had in their country houses, making them prime targets for the thieves. Another key reason, is that an honest solicitor was useless to a career criminal of that era. What was needed was a bent solicitor who could arrange for alibis and friendly witness statements and bribe police and witnesses. As the managing clerk at his law firm, Field was able to carry out these activities and encourage repeat business. On one occasion he described the contents and layout of a house near Weybridge where wife Karin had once been a nanny to a couple of criminals that he represented at various times in his career, Gordon Goody and Buster Edwards. He had arranged Buster's defence when he had been caught with a stolen car, and later met Goody at a nightclub in Soho. Field was then called upon to assist in the defence of Goody in the aftermath of the "Airport Job" which was a robbery carried out on 27 November 1962 at a branch of Barclays Bank at London Airport. This was the big practice robbery that the South West Gang had done prior to their grand scheme – the Great Train Robbery. Field was successful in arranging bail for Goody and Charlie Wilson.