Sir Roger Hollis was lucky he was only under house arrest.
It had been Airey Neave and Tom Harding-Grayson who had accompanied the Home Secretary, Roy Jenkins, to her rooms at King’s College on the night before the abominations at Brize Norton and Cheltenham to acquaint her with the ‘affair of the Cheltenham four’ — who had been incarcerated at Her Majesty’s Prison Gloucester by MI5 — and the true story of Great Britain’s glorious past age of cryptographic pre-eminence. Even now two-and-a-half weeks later every time she thought about that evening her mind turned somersaults of astonishment and bewilderment at the secret history that incredibly, nobody had thought to tell her about until that moment.
Nobody, that was, apart from four GCHQ departmental heads whose warning letter had been intercepted by MI5! Airey Neave had handed her the letter with the words ‘you will have a lot of questions you need to ask after you have read this, Margaret’.
That had proved to be something of an understatement much along the lines of ‘the cataclysm of the October War was a little bit unfortunate’.
‘Why on earth have I never heard about Bill Welchman and Alan Turing?’ She had demanded. Thereafter, the story had emerged at a rush. To her surprise Airey Neave — whom she had always known had never really detached himself from his wartime, 1939-45, Special Operations Executive and MI6 ‘friends’ — had deferred to the Foreign Secretary, whom she had never realised had had any kind of past history with the intelligence services.
Tom Harding-Grayson had started talking about the people who had broken the German codes and practically won the war!
‘Sit down, Margaret,’ he had suggested. ‘This will all come as a bit of a shock to you and yes, we ought to have had this little chat before now but well, so much has been going on and the sort of secrets we’re about to discuss are not really the sort of thing any of us ever thought we’d ever divulge to anybody.’
Airey Neave had chuckled at this point.
‘Not without somebody holding a gun at our heads,’ he remarked.
Completely flummoxed and somewhat vexed she had scowled at the two men.
‘Well, if it would help I’ll call in my AWPs so that they can hold guns to both your heads!”
Neither of her visitors had been entirely convinced that she was joking; and neither man doubted that if she asked her Royal Marine bodyguards — who took immense pride in styling themselves the Angry Widow’s Praetorians — to put guns to their heads that they would hesitate for a single moment.
Tom Harding-Grayson had tried to paint a picture.
‘There were four wicked uncles,’ he had explained. ‘Bill Welchman and Alan Turing, and Hugh Alexander and Stuart Milner-Barry; together they formed what one might call the brains trust that broke Enigma.’
‘Enigma?’ She had asked impatiently, not in any kind of mood to be subjected to a pointless history lesson about a war long won.
‘Enigma,’ the Foreign Secretary had echoed. ‘The Germans used a electro-mechanical cipher machine called Enigma which was so fiendishly proficient at encoding their communications that they, the Germans, never once during the war considered the possibility that anybody could break it. You see, a message enciphered using an Enigma machine could be converted into a plain text in which every character of every message could be encoded in billions of different ways. To cut a long story short the four Wicked Uncles first broke the Wehrmacht Enigma, then they broke the even more fiendishly complicated Kriegsmarine U-boat Enigma, and then they helped the Americans to break the Japanese equivalent to Enigma, the supposedly unbreakable JN-25 code. In so doing, the Wicked Uncles practically invented two entirely new sciences; the science of Traffic Analysis and the science of Electrical Computing. Alan Turing was also interest in a thing call AI, that’s Artificial Intelligence to simpletons like you. But that’s a whole story in itself.’
First Airey Neave had spoken of ‘Bill Welchman’. William Gordon ‘Bill’ Welchman had been thirty-three in 1939. He was a Marlborough schooled Trinity College mathematician who had been Dean of Sidney Sussex College, Cambridge. Alan Mathison Turing was twenty-seven at the start of Hitler’s war, an old boy of Sherbourne College who had at the tender age of twenty-two been elected a fellow of King’s College Cambridge for his proof of something called the ‘Central Limit Theorem’. Thirty-two year old Stuart Milner-Barry had become a city stockbroker after winning Firsts in Classics and Moral Sciences at Trinity College, Cambridge. As long ago as 1923 he had won the first British Boys’ Chess Championship and from 1932 onwards he had represented England at chess. The fourth Wicked Uncle was Irish-born Conel Hugh O’Donel Alexander, aged thirty in 1939, who like his friend Stuart Milner-Barry was a former Trinity College man and an international class chess player. Before the war he had taught mathematics at Winchester College. Earlier that year that idiot Hollis and his blundering underlings had arrested Hugh Alexander — one of the men who won the Second World War — for having had the courage to attempt to inform her that all was not well at GCHQ!
‘Bill Welchman ran Hut Six,’ Tom Harding-Grayson had explained. ‘Hut Six was in the business of attacking the German Army’s Enigma and Traffic Analysis.’
The Prime Minister had looked blank.
‘Traffic Analysis is what you do with the plain language part of every transmission,’ Airey Neave had offered, trying and failing to be helpful.
Tom Harding-Grayson had given him a look which asked: ‘Who is telling this story? You or me?’
Having settled this issue the Foreign Secretary had ploughed on regardless.
‘The only plain language parts of any given Enigma message — or of practically any intercept — are the FROM and the TO components, although to a casual observer these also will seem like apparently meaningless codes. However, once Bill Welchman and his people had worked out, for example that WA58Z was the Third Panzer Grenadier Regiment of the Second Panzer Division, and simple signal triangulation exercise established that it was mostly broadcasting from the vicinity of say, Amiens, Bill’s people owned WA58Z forever. For example, by the time of the Dunkirk fiasco at the end of May 1940 Hut Six had deduced the complete — and I do mean complete — German order of battle in the West. So, before we had actually broken a single Enigma message, Bill Welchman was able to pick up the phone and tell the powers that be not to worry about carrying on fighting the Battle of France because we had already lost it. Fortunately, that was just in the nick of time for the Navy to start pulling what was left of the British Expeditionary Force off the beaches of Dunkirk. Consequently, Winston Churchill did not get thrown out of Downing Street in early June 1940 and, eventually, we won the war.’
The Foreign Secretary had not worried overly if he was teaching his Prime Minister to ‘suck eggs’. It was critically important that she understood exactly what HMS Alliance had captured on the Mareşal Fevzi Çakmak.