On a recent short holiday break in Oxfordshire I decided to take in a visit to Bletchley Park in Milton Keynes, Buckinghamshire, which was the central site of the United Kingdom’s Government Code and Cypher School (GCCS) during the Second World War and which regularly penetrated the secret communications of the Axis Powers – most importantly the German Enigma and Lorenz ciphers.
The official historian of World War II British Intelligence has written that the “Ultra” intelligence produced at Bletchley shortened the war by two to four years, and that without it the outcome of the war would have been uncertain.
Bletchley Park rejoices in the fact that, until fairly recently, it was probably Britain’s best kept secret. This is because the secrecy surrounding all the activities carried on here during World War Two was of vital importance to our national security and ultimate victory. There are some who still refuse to divulge what they did at BP because they signed the Official Secrets Act and simply saw this as a binding agreement and a matter of honour.
The GC&CS mission was to crack the Nazi codes and ciphers. The most famous of the cipher systems to be broken at Bletchley Park was the Enigma. There were also a large number of lower-level German systems to break as well as those of Hitler’s allies.
Whilst visiting the site, set in the beautiful grounds of a country mansion, it is difficult to imagine the stress and pressures that staff worked under trying to crack the German and other Axis power codes. The infamous huts they worked in are stark, dimly lit and have something of an oppressive air about them but it is here that work was done 24 hours a day, 7 days a week trying and succeeding in breaking many codes.
The first operational break into Enigma came around the 23 January 1940, when the team working under Dilly Knox, with the mathematicians John Jeffreys, Peter Twinn and Alan Turing unravelled the German Army administrative key that became known at Bletchley Park as ‘The Green’. Encouraged by this success, the code breakers managed to crack the ‘Red’ key used by the Luftwaffe liaison officers co-ordinating air support for army units. Gordon Welchman, soon to become head of the Army and Air Force section, devised a system whereby his code breakers were supported by other staff based in a neighbouring hut, who turned the deciphered messages into intelligence reports.
It is important to recognize “the prewar work of Marian Rejewski, Jerzy Rozycki and Henryk Zygalski mathematicians of the Polish Intelligence Service, in first breaking the Enigma code. Their work greatly assisted the Bletchley Park code breakers and contributed to the Allied victory in World War II.” This contribution is acknowledged and commemorated by the Polish Memorial in the grounds of Bletchley Park
As one tours the venue there are illustrations of the mathematical models that Turing and his colleagues were working on to try and crack the codes and it is no surprise that in the visitors book there are several comments along the lines of “I still don’t understand how they did it” because of the complexity of these models.
What should not be forgotten in all of this is the fact that over eight and a half thousand people were involved with BP and seventy five per cent were women who perhaps have never been given the recognition they deserve.
There were motorcycle dispatch riders who travelled the country delivering highly secret messages to the various intelligence bases (some of these were women) and without whom, the system could not have functioned effectively.
Until relatively recently Bletchley Park was under threat of closure but now has been saved and developed as a museum in recognition of the invaluable work done by the code breakers during WW2.
Do visit it, it is a very important part of our recent history and without the work of many of the unsung heroes we could be living under a very different regime than that we enjoy today.