Established in late August 1938, Bletchley Park became the very secret location for the establishment of the UK Government Code and Cypher School whose mission was to crack the Nazi codes used to encrypt and transmit signals to their operational units.

The Enigma Machine Cypher was the most famous and important one to be 'cracked at Bletchley Park.

A bank of AR88D radio receivers listened out for encrypted Nazi radio teletype or morse code transmissions.

In December 1943, Colossus, the world's first programmable electronic computer was built in secret to rapidly speed up the 'breaking' of the German Military cypher codes.

A little technical but every listened intently !

The front panel of Turing's BOMBE - an electromechanical devise used to 'unlock' the German cypher code

The Germans changed the ENIGMA Codes every day at midnight and so Turing's Bombe was developed to keep up with the pace of such code changes. Housed within a bomb proof shelter banks of these machines, operated by Wrens, ran 24 hours a day cracking the codes in use. Despite having been destroyed under orders from Churchill after the War, the machine has been lovingly recreated to full working condition by devoted enthusiasts at Bletchley Park.

If you are really interested in learning more about the theory and practicalities of code breaking visit the following website by clicking on the link.  http://www.codesandciphers.org.uk/