Barings was Britain's oldest merchant bank. It had financed the Napoleonic wars, the Louisiana Purchase, and the Erie Canal. Barings was the Queen's bank. During the Second World War, the British Government used Barings to liquidate assets in the United States and elsewhere to help finance the war effort. After the war Barings was overtaken in size and influenced by other banking houses, but remained an important player in the market.
Leeson was born in Watford, north-west of London. He attended Parmiter's School. After leaving school in the early 1980s, he landed a job as a clerk with the exclusive private bank, Coutts, followed by a string of jobs with other banks, ending up with Barings in the early 1990s.
At Barings, he worked in operations, but shortly after joining Barings, he applied for and received a transfer to the Far East. His first task when he arrived was working through a back-office mess in Jakarta. The bank was sitting on £100 million in stock certificates and bearer bonds that were not in deliverable form. Many of the stocks had been purchased on behalf of clients. Because the stock market had subsequently declined, the clients trying to avoid taking delivery—they complained that certificates were in the wrong denomination, not properly documented or in physically unacceptable condition. Over a period of 10 months, Leeson worked his way through the certificates, addressing the problems and making delivery.
Leeson’s accomplishments in Jakarta attracted the attention of Barings management. In 1992, he applied for a position within Barings Securities(Singapore) Limited, they not only accepted him, but they made him general manager with authority to hire traders and back office staffs.