Picture: The main house at Bletchley Park (Image: PA)
In World War Two Buckinghamshire, Bletchley Park was the site where British codebreakers worked to thwart Nazi Germany by breaking coded messages.
To those who worked there, it was known by several different cover names, including 'Station X', and 'B.P.'
Established in 1938, the intelligence generated from the site's huts had an impact on all services involved in the war effort.
The Enigma machine used by the German military had the potential for nearly 159,000,000,000,000,000,000 combinations when creating ciphered messages.
An Enigma machine on display at Bletchley Park. Image: PA
In response, the UK created their own team in order to break the complex system.
Dilly Knox, a
codebreaker from the First World War, recruited a crack group, including Alan Turing, to begin working out of Bletchley Park's collection of small buildings.
Using the Enigma machine, encrypted messages were sent from Berlin using the Lorenz - rotor stream cipher machines, to German troops in the battlefield.
Once the first German coded messages were deciphered in early 1940, the team were on their way to victory.
Despite not seeing one of the machines once during the war, the team in Buckinghamshire were able to counter it with their own creations.
One of the UK's big hitters in their decoding arsenal - the Turing Bombe machine. Image: PA.
The giant Colossus machine reduced the time it took the team to decrypt messages from weeks to hours, while Turing's Bombe, originally designed by its namesake, was an essential tool in unlocking parts of the Enigma code.
Significant results were seen in the skies above Europe, as messages to the German Luftwaffe were cracked, allowing Britain to anticipate the aircraft's whereabouts.
This meant the RAF were often one step ahead, providing opportunities to surprise German pilots in the air, while bombing could be better defended from the ground.
This breakthrough proved crucial for the Allies' success in Normandy during D-Day.
Royal Marine commandos move off the Normandy beaches in 1944. Image: PA.
The work done at Bletchley Park also impacted the war being fought at sea.
Cracking the 'Dolphin Enigma' was critical as this was the coding system used by Germany's U-boats at sea.
Figuring this out and cracking the Italian ciphers lead to key victories, including in the Battle of Matapan which saw a Royal Navy victory in the Mediterranean.
General Dwight D. Eisenhower, then the Supreme Allied Commander, Allied Forces,
expressed his gratitude to the Bletchley Park team in a letter:
"The intelligence... has been of priceless value to me.
"It has saved thousands of British and American lives."
The future US president ended his letter by expressing his "sincere thanks" to the codebreaking team, "for their very decisive contribution to the Allied war effort".
Cover picture is courtesy of the Fitzwilliam Museum.