We reveal how the Enigma codes were cracked this morning
Until the 1970s almost nothing was known about the brilliant minds who helped bring World War Two to an end.
Hidden away at Bletchley Park they managed to crack secret codes the Nazi regime had believed unbreakable. The star-studded movie "Enigma" gave some insight into how they did it.
But now there's even more information available on how the work was done.
This morning on Breakfast, we can reveal exactly how the German Enigma codes were cracked - using huge machines called British Turing Bombes.
And for the first time since the end of the War we can see one in action.
The Turing Bombe machine: 200 were built to crack the Enigma code
Breakfast's Sarah Campbell was at Bletchley Park this morning.
It's taken enthusiasts ten years to rebuild a Turing Bombe machine - and it'll be working and on display at Bletchley Park for the first time.
The machines were used to calculate the millions of possible combinations used by the Enigma machines
They were able to crack the codes using the information that the British human code crackers had already accessed, by listening to the messages that the German commanders were sending one another on their famous Enigma machines.
For more details on visiting Bletchley, please follow the link on the right hand side of the page