Leo Marks: Master Of Codes

Contemporary Review, June, 2001 by Jonathan W. Doering

LEO Marks, who died in January, made a startling impact in different spheres: as an intelligence officer and script writer. In view of his characteristic discretion, it seems inevitable that it was only in the last few years of his life that his name came to be known widely, both through the critical rehabilitation of Michael Powell's film, Peeping Tom, which Marks wrote, and his book, Between Silk and Cyanide, a gripping account of his role in British code operations during the Second World War. Yet this small legacy will serve as a rich repository of images and puzzles to delight us for some time to come.

Marks was the only child of Benjamin Marks, a partner in the bookshop at 84 Charing Cross Road, later made famous by Helene Hanff in her eponymous story of her letter-relationship with one of Benjamin's employees, Frank Doel. Marks showed early precocity, when at the age of eight during one of his many Saturday morning visits to the bookshop, he was left to read a first edition of Herman Melville's The Gold Bug. He cracked his father's secret coding system for prices by studying the coded label on the back of the book. The story itself tells of a hidden treasure protected by a secret code: Leo's destiny was prefigured in this, as well as in the treat his mother allowed him after his weekend apprenticeship: a trip to the cinema matinee.

Educated at St. Paul's, Marks narrowly avoided expulsion for organising an inter-school exam cribbing network because his headmaster was a customer of Marks and Co. He was called up for war service at the age of twenty in 1942, 'escorted to the war by my parents in case I couldn't find it on my own'. With no taste for combat, he had wondered if he might find a niche in cryptography. After numerous fruitless applications to the Forces and the War Office, he contacted an acquaintance of his father's, who also happened to be a Major attached to Special Branch. Marks was then sent for training at the Government Cipher School in Bedfordshire. This course was normally preparatory for entry into the main signals section, Bletchley Park, and this was indeed the destination for Marks's twenty fellow students. He, however, had gained a reputation as a maverick in his first week, showing little patience with the more pedestrian training exercises, instead cracking a code in a matter of days that had been intended to occ upy a team for a whole week. Nevertheless, his training officer branded him 'difficult to place', sending him to be looked over by a discreetly titled department, the Inter Services Research Bureau at 64 Baker Street, London. This nondescript title was in fact camouflage for the dashing and enigmatic Special Operations Executive (SOE), an intelligence service set up in parallel with MI6 in 1940 by Churchill to 'set Europe ablaze' with sabotage, subversion, and resistance.

Marks spent the whole of his first day cracking a code that he had been expected to complete in twenty minutes. As he turned to leave under the withering gaze of his disappointed superiors, it was discovered that he had not received the decryption code that accompanied the exercise. It was a characteristically idiosyncratic debut which saw Marks soar to become Head of Codes at SOE by the age of twenty-three.

When Marks began at SOE, many messages transmitted from Occupied Territories were deemed 'indecipherable', jargon for being so garbled as to be unintelligible. This was one example of bureaucratic laziness he set about to change. In his role as Head of Codes, he oversaw a team of 400 code breakers, creamed from the voluntary First Aid Nursing Yeomanry (FANY). Marks shaped this group into an excellent cryptanalysis department, with the motto 'There shall be no such thing as an indecipherable message'. An eccentric himself, he sought out brilliant misfits capable of lateral thinking, raising eyebrows at the Ministry of Labour with the instruction, 'Do not reject any girl on grounds of insanity without first offering her to SOE'.

It was standard procedure for agents to be asked to transmit indecipherables again, every communication risking detection by Nazi direction finders. The consequences for those caught were, of course, horrendous. The mild-mannered Marks inspired his team with an ad hoc address about an eighteen-year-old Yugoslav partisan caught after being asked to transmit a message a second time. His corpse had been taken to the morgue hours later, 'unrecognisable as a human being'. Marks not only dedicated himself to cracking all messages sent back to Britain, but also to improving the coding system SOE relied on. Ironically enough for the author of the immortal poem The Life That I Have, he quickly identified the drawbacks of using traditional poem codes. For years, British Intelligence had been using a system that involved taking a poem and selecting five words from it to encode the message. Favourites used included works by Tennyson, Keats, and Shakespeare. Literate German officers could quite easily identify the poetry used for this, risking the integrity of an agent's traffic. One agent was even allowed to use the first verse of the National Anthem. Marks argued that agents should either write their own poems, or else have original ones written for them.