Jewish writer, screenwriter, and cryptographer. Leopold (Leo) Samuel Marks, MBE, was Chief of Codes at Special Operations Executive (SOE) in WW2. He was a key trainer of secret agents sent to defeat the Nazis.
Born in London, the son of an antiquarian bookseller in Charing Cross Road (whose shop Helen Hanff wrote about in '84 Charing Cross Road').
Already interested in cryptography he was conscripted in January 1942 and immediately sent on training in the subject. As head of SOE he had a staff of 400. One of his responsibilities was to provide agents with the ciphers, initially based on poems, with which to send information to London by radio. To ensure the poems were unknown he took to using ones he had written himself. One famous and moving example is 'The Life That I Have' given to Violette Szabo. This was a poem he had written following the death of his girlfriend in a plane crash.
After the war, Mr Marks became a playwright and screenwriter, often writing scripts that drew on his war-time experiences. He wrote the script for the controversial 1960 film Peeping Tom.
In 1998 Marks published an account (written in the 1980s) of his work in the SOE, 'Between Silk and Cyanide'. It seems that this aggrandises his own contributions and criticises everyone else.