Mary Blood (Mary Coombs)

1929 - 2022

Mary Coombs (nee Blood) was the first woman to work on the Lyons Electronic Office (LEO) computers. She didn't take the typical route to becoming a computer programmer; she earned a BA Honours degree in French from Queen Mary University in London and then took a holiday job at Lyons, the well known catering company with a chain of tea shops (known as Lyons Corner Houses) throughout the UK. Despite not studying maths formally, her maths skills led to a place with Lyons’ Statistical Office and there Mary learned of an opening with the department working on the LEO computers.

LEO was the world’s first computer used exclusively for business applications. Mary completed Lyons’ ‘computer appreciation course’ with a stellar performance that led to an offer of a job in the computer division with Frank Land, working on the LEO from 1952 on. 

Mary worked on programming the LEO to handle payroll. She is recognised as the first female commercial programmer. She became a supervisor and worked to locate and repair coding errors in the programs created by others. She worked on the LEO I, II, and III and her experience led to her being in charge of rewriting the programs from LEO II to be used on LEO III. She went on to work for English Electric LEO Computers and International Computers Limited as these companies eventually merged.

Mary Coombs was one of the women profiled in our Women in Computing Festival 2017 entitled Where Did All the Women Go?. Click here for the Women in Computing timeline created for that event.

Obituaries for Mary Coombs can be found at The Times, Computer Weekly, Computing, BCS, The Register, The Guardian, The Telegraph, the ACM, The Elective, The Independent and BBC Radio 4’s  Last Word on Friday 18th March 2022.

On Friday 25th March 2022 LEO Computers Society held a Zoom Forum for members. The Forum was devoted primarily to paying tribute to Mary Coombs. Hilary Caminer presented a number of photos of Mary and other relevant material and Frank Land paid a personal tribute to her life. A recording of the event can be found on the LCS website.

The Society's newsletter LEO Matters published an obituary for Mary Coombs in June 2022.

Photo courtesy of Mike Hally / LEO Computers Society.