Bletchley Park's legacy as WWII winner overstated - GCHQ historian

The role played by codebreakers at Bletchley Park in Britain’s victorious war effort against Nazi Germany is regularly overstated, a new history of UK spy agency GCHQ claims.

In Behind the Enigma, released on Tuesday, Professor John Ferris casts doubt on the “cult of Bletchley”, which he claims has protected GCHQ and boosted its reputation.

The spy agency was set up as a peacetime “cryptoanalytic” unit in 1919. After World Word Two broke out staff were moved to Bletchley Park country estate in Buckinghamshire, where intelligence analysts famously cracked the Nazi’s Enigma code.

An official history in the war had previously claimed that the breakthrough had shortened the conflict by two to four years, and without it the outcome would have been uncertain.

But Prof Ferris told the BBC: "Bletchley is not the war winner that a lot of Brits think it is.

“Intelligence never wins a war on its own”.

The work of the mathematicians at Bletchley – where women made up 75 per cent of the workforce – was immortalised on the big screen in the 2014 blockbuster The Imitation Game, starring Benedict Cumberbatch as codebreaker Alan Turing.

Although Polish mathematicians had worked out how to read Enigma messages and had shared this information with the British, the Germans increased its security at the outbreak of war by changing the cipher system daily.

This made the task of understanding the code even more difficult.

(Channel 4)

Cracking the code meant that Allied convoy ships could be steered away from the German’s lethal U-boat 'wolf-packs'. Turing’s role was essential in turning tide for the Allies during the Battle of the Atlantic.

Behind the Enigma charts the history of the agency through the 20th century, from its origins and work during World War Two, through to the Falklands Wars and its response to the leaks by whistleblower Edward Snowden.

Prof Ferris writes that despite having access to top secret documents, he was given the freedom by the spy agency to come to his own conclusions.

"GCHQ is probably Britain's most important strategic asset at the moment and will probably remain that way for generations," he says.

"I think that Britain gains from keeping it strong and world class, but at the same time, you need to put in proportion what it is you can and cannot get from intelligence."

In a foreword, the current director of the intelligence agency, Jeremy Fleming writes: "GCHQ is a citizen-facing intelligence and security enterprise with a globally recognised brand and reputation. We owe all of that to our predecessors."