During the Second World War, Asa Briggs was just one of a whole generation of the brightest people in Britain (and some from Poland, France and the USA) who worked at Bletchley Park, breaking enemy codes. The process – given the codename ‘ULTRA’ – played a key role in the Allied victory. To make it work, the British government’s foreign intelligence service, MI6, recruited some of the cleverest people they could find. Because so much of the recruitment was through personal connections or Oxford and Cambridge universities, they tended to be more upper class than the population at large.
Eventually, more than 10,000 code-breakers worked at Bletchley Park – where the gardens had been filled with temporary huts – or at other locations which it controlled. One thing that they all had in common was that they were all sworn to secrecy: never to talk about their work. The British realised that if their enemies knew that their codes were being broken, they would change them, and might even take steps to make the codes genuinely unbreakable. So the intelligence derived from Bletchley was only ever shared with the highest army commanders in each front.
The British secrecy held, and despite some close shaves, the German, Italian and Japanese militaries never suspected how much of their traffic was read. The Bletchley workers followed orders to keep mum after the war, too. It was not until 1975 that the UK government relented, giving Group Captain Winterbotham, the RAF intelligence officer who had helped set up ULTRA, permission to tell the truth in his memoirs.
The Bletchley connection linked many people who later gained power, prominence (and sometimes fame) in post-war Britain, particularly in academia and the law. Often, knowledge of their secret lives gives a real insight into their professional achievement. I suspect that we can trace some of Asa Briggs’ faith in the ability of an institution do amazing things back to his Bletchley days. Labour politician and Bletchley alumnus Roy Jenkins was one of the first champions of the UK’s participation in European union: he was joined in Brussels by the Conservative peer Lady Elles, who had also worked at Bletchley. Mary Siepmann worked in MI6’s codebreaking team in London and in later life found fame as the novelist Mary Wesley, whose characters were often more than they seemed.
Bletchley also played a role in the postwar development of computing, which those concerned had to keep secret. The mathematician Maxwell Newman led the design work on Bletchley’s pioneering COLOSSUS codebreaking computer, and immediately after the war he built on this expertise to help build one of the world’s first electronic computers at Manchester University. The gifted electronic engineer Tommy Flowers, who built COLOSSUS, created Britain’s most famous ‘computer’ in 1957, the random number generator ERNIE which chose the weekly winning Premium Bond numbers. The mathematician Alan Turing did brilliant and well-known work on the theory of both codebreaking and computer design. He was hounded for his homosexuality: another codebreaker, the novelist Angus Wilson, was in the 1960s one of the most prominent activists for gay rights.
The 2014 film The Imitation Game unfairly accuses Turing of being aware of spying by the USSR at Bletchley. He wasn’t: but such spying did go on. John Cairncross, who later rose to high rank in the UK intelligence services, was one of the ‘Cambridge spies’. He was later unmasked and sacked, but never prosecuted. And whatever he told his handlers about Bletchley, they kept it secret too.
In the follow audio track, I look at a key moment in code-breaking history and what it can tell us about how to treat ‘eye-witness testimony'.