The British LEO I (Lyons Electronic Office I) computer ran its first business application in 1951. The computer, modelled closely on the Cambridge EDSAC, was the first computer used for commercial business applications. It was built by J Lyons and Co, and eventually became part of English Electric Company (EELM) and then International Computers Limited (ICL).
J Lyons and Co, one of the UK's leading catering and food manufacturing companies in the first half of the 20th century, sent two of its senior managers to the USA in 1947 to look at new business methods developed during the Second World War. During their visit they came across digital computers then used exclusively for engineering and mathematical computations. They saw the potential of computers to help solve the problem of administering a major business enterprise. They also learned that Cambridge University, back in the UK, was actually building such a machine, the pioneering EDSAC computer.
On their return to company headquarters in London they made a recommendation to the Lyons' Board that Lyons should acquire or build a computer to meet their business needs. This was accepted, and it was agreed that Cambridge University should receive some financial support if the University of Cambridge Mathematical Laboratory gave some help to the Lyons' initiative.
Cambridge provided training and support for the Lyons' engineers. By 1949 they had the basics of a computer specifically designed for business data processing running and on 17 November 1951 rolled out the first commercial business application. The computer was called the LEO—Lyons Electronic Office.