Sir David's childhood was as conventional as starch. His father, a partner at Guinness Mahon, sent him to a public school in Berkshire, followed by national service with the Rhine Army. He then dropped out of Oxford University after one, largely sociable, year.
The incident gave an early hint of the unconventional attitude and pragmatism that have characterised his subsequent career. He joined Warburg in 1964 and became a director in 1981. As the Big Bang approached, he decided big was better, jumped in with both feet and bought three leading stock market firms early enough to execute their integration.
For a while he and Warburg could do no wrong. Sir David was more than once tipped as a potential future Governor of the Bank of England. The last two years have been more difficult. Now 59, Sir David will have to postpone his retirement and manage one more problem. "We have been through difficulties before and will survive them again," he told his staff.