It is now more than 60 years since the world’s first business use of a computer, the valuation of bakery output, was rolled-out on the LEO I computer at Cadby Hall in London, the headquarters of the food production and catering company J. Lyons and Company. LEO I had been designed and built as a computer to be used for business data processing by a team of engineers recruited by Lyons, with a basic design following the design of the Cambridge University EDSAC. The story of the Lyons initiative has been recorded and explanations of how a company in the food business came to build a computer has been told in books and articles in the last decades (- see Appendix 1 for a comprehensive bibliography of material relating to LEO). This chapter remembers the contribution made by LEO.