Tony Comer – who has worked for GCHQ for 36 years and has spent the last 10 as its historian – picks high-profile moments from its history.
More than 80 veterans who played a vital but secret role in the efforts to end the Second World War gathered to mark the 80th anniversary of the start of the conflict.
An Aberdeen University graduate, Helene Aldwinkle, has just been awarded the Legion d'honneur by the French Government for her work at Bletchley Park during the Second World War.
Aberdeen University graduate Helene Aldwinkle presented with Legion d’Honneur for Bletchley Park work
She was just 21 when she was recruited from Aberdeen University to join the crucial work being done at Bletchley Park.
Joe Public gets a whistle-stop tour behind the scenes of Britain's Second World War code-breaking nerve centre in this official history.
For 50 years Margaret Beedie was sworn to secrecy for her role in Britain's war effort - but when that time elapsed the modest islander still kept her lips sealed.
A black and white photograph of her bomber pilot husband takes pride of place on the television sideboard, while paintings of war planes adorn the wall.