As the war progressed, Station X became a hidden city of 10,000 people working in hastily constructed “huts”. Many of the codebreakers were tweedy, pipe-smoking Cambridge mathematicians, both dons and recent graduates, but some were recruited because of their linguistic skills, knowledge of hieroglyphics, or brilliance at chess. All were expected to be able to solve the Telegraph crossword in less than six minutes. Many were eccentric. One boffin would pace around the lake drinking coffee as he pondered, and when he had finished his cup he would look at it in surprise, as if unsure how it had got into his hand. He would then toss it over his shoulder in to the lake.
At the end of the war, Churchill ordered that all records of the place be destroyed in a huge bonfire. Had one former employee not written a book in 1974 about his work there, we might have remained in the dark about Bletchley to this day. As it was, the world was astonished.
Indignant too, because Alan Turing, the genius who did most to crack the German Enigma codes and shorten the war by at least two years, was treated appallingly after the war, on account of his homosexuality. He was prosecuted for “gross indecency” in 1952 and given hormone treatment – “chemical castration” – which led to his suicide two years later. He was given a posthumous royal pardon in 2013.
The Bletchley story is told in new film The Imitation Game, starring Benedict Cumberbatch as Turing
A critically acclaimed new film, The Imitation Game, celebrates his work at Bletchley Park. As played by Benedict Cumberbatch (in what is being tipped as an Oscar-winning performance), Turing is revealed as an insensitive narcissist who found eye contact difficult, but who was very much the right man at the right time. Apart from saving millions of lives, he also had a hand in the invention of the world’s first programmable computer at Bletchley, a giant machine called Colossus that enabled him to crack codes quickly, by a process of elimination.
Everyone has heard of Turing now, and rightly so, but, as this film reminds us, he was part of an extraordinary team, some brilliant, others unprofessional, one treacherous. So who were they? Well, the second most important person at Bletchley was Hugh Alexander.
Hugh Alexander (played by Matthew Goode) – British chess champion
Hugh Alexander; Matthew Goode as Hugh Alexander in The Imitation Game
Like many of the codebreakers, he had a first in mathematics from Cambridge, but he found himself in Hut 6 in 1940 thanks to his brilliance at chess. Twice British chess champion, and an International Master, he made important contributions to two classic chess strategies: “the Dutch defence” and the “Petroff defence”. Had he been allowed to compete in the Soviet Union during the Cold War – the authorities here thought the contents of his brain too valuable to allow him to go anywhere near there – he may even have become a world champion.
He was known in print at Bletchley as C.H.O’D – his full name was Conel Hugh O’Donel Alexander – which sounds like a cryptic crossword clue. Perhaps not quite as dashing as the actor Matthew Goode who plays him in The Imitation Game, Alexander nevertheless had a reputation for urbanity and charm. In 1941, he was transferred to Hut 8 and became Turing’s deputy.
The great man would tease Alexander for being almost, but not quite, his intellectual equal.
According to a memoir written by one of his colleagues: “We all thought Hugh was crazy. Tall, blond, huge blue eyes, never stopped talking, a terrible energy.” And in the words of another: “We worked [at Hut 8] through the war on a continuous three-shift basis. The night shift was not generally popular because everybody quickly became tired through lack of proper sleep in the day; but Hugh had a strange passion for working at night and used to put himself on nights for weeks on end. This did not prevent him working much of the day as well – he seemed to thrive on this strange regime.” Alexander’s admiration for Turing was conditional – he found him annoying most of the time – and he eventually engineered a friendly coup against him to become the head of Hut 8. He did this because he rightly saw that Turing’s gifts were being wasted on the admin side of running things: he needed thinking space. It was Alexander, more than anyone else, who recognised Turing’s genius for what it was.
Station X was run in quite an amateurish way by MI6. Such was the lack of professionalism, in fact, Alexander and Turing broke with protocol and went over the heads of their MI6 superiors to make a direct appeal to the Prime Minister, requesting more equipment and personnel. Churchill responded instantly, agreeing to the requests and notifying his Chief of Staff. His memo was stamped with that memorable phrase of his: “Action This Day.” When the Germans introduced a “super enciphered” method of transmitting the day’s settings to their Enigma operators (using bigram tables), Alexander helped Turing develop a technique for breaking them called Banburismus, because it involved “punched holes on long sheets of paper printed in Banbury”.
Alexander also introduced a pneumatic tube system for transferring files and documents between huts. He had borrowed the idea from his pre-war job, working as the chief scientist with the John Lewis chain.
After the war he became head of cryptanalysis at GCHQ. He died at the age of 64 in 1974 and there has been speculation that the stresses caused by the mental demands of his career led to his early death.
The Colossus computer at Bletchley, used to decode Nazi messages. Photo: Alamy
Joan Clarke (played by Keira Knightley) – female codebreaker who became engaged to Turing
Keira Knightley as Joan Clarke in The Imitation Game
Joan Clarke, by contrast, was a much calmer, less intense character, which is perhaps why she lived until 1996, long after she retired from GCHQ. Like Alexander, she had a first in maths from Cambridge; unlike him, when she was recruited to Bletchley Park she was told that her work there wouldn’t really require mathematics.
This turned out not to be the case. After a period of clerical work with “the girls”, her mathematical gifts led to her becoming the only woman among a team of nine Banburists. And according to her boss, Alexander, she was “one of the best Banburists in the section”. Clarke wasn’t as glamorous as Keira Knightley, who plays her in the film, but her character is captured well by the actress. Records describe her as “congenial but shy, gentle and kind, non-aggressive and always subordinate to the men in her life”. Her enthusiasm and energy were legendary. She would often be reluctant to hand over her workings at the end of her shift and instead continue to see if a few more calculations would produce a result.
A pay rise was arranged to recognise her contributions to the team and she was promoted to “Linguist” even though she spoke no other language. She delighted in answering a questionnaire with “Grade: Linguist. Languages: none”.
In the spring of 1941, she developed a close friendship with her Hut 8 colleague Turing. For a time, they became inseparable, with Turing arranging their shifts so they could work together. One day, in his awkward way, he proposed marriage to her and when Clarke accepted he added, “But don’t count on it working out as I have homosexual tendencies.” The romance continued regardless, unconsummated, until they called it off by mutual consent a year later.
Clarke became deputy head of Hut 8 in early 1944 and, after the war, she married an Army officer she had met when working at GCHQ.
Decoder Wrens working in Huts 6 and 8 at Bletchley Park during the Second World War
Stewart Menzies (played by Mark Strong)
Stewart Menzies (Photo: Getty); Mark Strong as Stewart Menzies in The Imitation Game
Arguably, the next most important figure at Bletchley was Stewart Menzies. His grandfather was a wealthy whisky distiller and his parents were friends of Edward VII, who was rumoured to be Menzies’s real father. At Eton he was sporty but never academic, and he didn’t go to university afterwards but joined the Life Guards instead.
At the start of the war he became “C”, the head of MI6. Churchill was initially sceptical about whether Menzies was up to the job, but he eventually made him part of his inner circle and Menzies would report to him daily.
Though not a codebreaker himself, it was Menzies who was in overall charge at Bletchley, and it was he who introduced what was called Ultra. If too many of the intercepts from Bletchley were acted upon, the Germans would get suspicious that the Enigma codes had been cracked. Menzies therefore introduced a system that meant only a certain percentage of the intelligence gleaned from decoding would be passed on to the British Army, Navy and RAF.
In addition to being married three times, he had a long-term affair with his secretary. He retired with the rank of major general.
John Cairncross (played by Allen Leech) – loner later revealed to be part of the Cambridge spy ring
John Cairncross; Allen Leech as John Cairncross in The Imitation Game
It is implied in the film that Menzies knew exactly what the spy John Cairncross was up to at Station X. An intelligent, spiky man, Cairncross was described by his colleagues at Bletchley Park as “a bit of a loner”.
This was an understatement given that he was the Fifth Man in the Cambridge spy ring. He knew Kim Philby and Anthony Blunt, but didn’t like them much.
He admitted to spying in 1951 when Guy Burgess fled to Moscow and MI5 found a handwritten note from him in Burgess’s flat.
Cairncross arrived at Bletchley Park in 1942 and went to work in Hut 3 on Germany Army group communications. Unusually for a codebreaker, he read languages at Cambridge, rather than mathematics.
Throughout the war, Cairncross passed documents through secret channels to his KGB handlers, who gave him the code name Liszt, because of his love of music. He smuggled the decrypts out of the hut in his trousers, transferring them to his bag at the railway station.
But the truth is probably more ambiguous than this summary of his treachery allows. The Allies wanted the Soviets to know about certain German battle plans, just not where the intelligence came from. They were our wartime allies, after all.
Given the tight security at Bletchley, there is speculation that Menzies arranged things so that Cairncross was fed with documents that he wanted the Soviets to see. It seems the only explanation for why only the most relevant decrypts were left conveniently lying around, and why Cairncross was never searched as he left Bletchley.
Peter Hilton (played by Matthew Beard) – maths genius and inventor of one of the world’s longest palindromes
Peter Hilton; Matthew Beard as Peter Hilton in The Imitation Game
Our next notable Bletchley figure could not have been more different from prickly Cairncross. Unusually for a Bletchley Park mathematician, the precocious, sweet-natured Peter Hilton had studied at Oxford rather than Cambridge. He was recruited in 1942 at the tender age of 18 because he also knew German (a language he had taught himself in a year). He worked alongside Turing in Hut 8 on Naval Enigma and, thanks to his extraordinary powers of visualisation, he was able to unpick in his mind’s eye streams of characters from two separate teleprinters – a feat of mental gymnastics that proved vital when the Germans introduced a new system of teleprinter ciphers produced by a much larger and more complex machine than Enigma.
Many years after the war, this was revealed to be a Lorenz SZ40 encoder, but, at the time, staff at Bletchley Park called it “Tunny”.
In his off-duty hours, Hilton (played by Matthew Beard in the film) earned a reputation as a convivial companion.
He was a regular in the bar of the Bletchley pub that was subsequently renamed The Enigma, and often attended dances at nearby Woburn Abbey, where Wrens were billeted. He also became a renowned exponent both of bawdy songs and dirty jokes and once spent a sleepless night composing one of the world’s longest palindromes: DOC, NOTE: I DISSENT. A FAST NEVER PREVENTS A FATNESS. I DIET ON COD.
After the war, Hilton became a professor of mathematics at Cornell University and helped create a new discipline, homology theory. Once the Official Secrets Act was lifted in the Eighties, his lectures about the years at Bletchley Park became highly popular at venues all over the world.
“For me,” he recalled in one of them, “the real excitement was this business of getting two texts out of one sequence of gibberish. I never met anything quite so exciting, especially since you knew that these were vital messages.”
Jack Good (played by James Northcote) – once cracked a code in his sleep
Jack Good, right, once cracked a code in his sleep. Photo: Des Good
And so we come to our final unsung Bletchley hero. Jack Good was a slender, good-humoured, bushy-moustached mathematician (Cambridge) who worked closely with Turing in Hut 8 and was prone to having catnaps on the floor of the hut, especially after a long shift. This was just as well because he broke one vital code in his sleep, with the solution coming to him in a dream. In it he wondered whether the dummy letters German telegraphists had to add to their messages in order to transmit them were random, or whether there was a bias towards particular letters. After inspecting some messages that had been broken, he discovered that there was a tendency to use some letters more than others. This being the case, all the codebreakers had to do was work back from the indicators given at the beginning of each message, and apply each bigram table in turn. The bigram table that produced one of the popular dummy letters was probably the correct one.
When Good (played by James Northcote in the film) mentioned his discovery to Turing, the genius felt embarrassed, and said, “I could have sworn that I tried that already.” It quickly became an important part of the Banburismus procedure.
After the war, Good became a professor and worked as a consultant to Stanley Kubrick on the 1968 film 2001: A Space Odyssey. He never guessed Turing’s sexual orientation in all the time they worked together, and neither did the Bletchley Park authorities. “Otherwise,” as Good noted matter-of-factly, “Turing may have been driven to kill himself earlier, and we might have lost the war.”
The Imitation Game is on release now