The WWII female codebreakers
For thousands of women during the Second World War an ugly Edwardian mansion in Buckinghamshire was called home.
Day after day, they decoded messages about upcoming attacks, learned about the Nazis' plans for the Holocaust and ultimately read the communiqués that revealed the Germans' fear of defeat.
Yet these unsung heroines - who included Kate Middleton's grandmother - couldn't tell anyone about their critical contribution to the war effort and it's only now that they're breaking decades of silence to talk about the extraordinary time.
The intelligence centre and its work was conducted under conditions of strictest secrecy and Churchill once described Bletchley staff as: "The geese that laid the golden eggs and never cackled."
A total of 12,000 people worked there, with 80 per cent of them women - one of them was Joan Clarke, the cryptologist who worked closely with Engima machine genius Alan Turing, and was played by Keira Knightley in the Oscar-nominated film, the Imitation Game.
Now more than 70 years later, 45 women have shared their stories in The Debs Of Bletchley Park And Other Stories by its chief historical adviser, Michael Smith.
From sleeping in huts so cold their flannels froze over night to wading through reams of paper each day, these women may have been closeted away in London's commuter belt but in many ways they were at the frontline of the war effort.