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Bletchley Park: England's Secret Codebreaking Base
Its January 1940 and the war in Europe has been raging for months. At a rural mansion known as Bletchley park, less than 50 miles from bustling London, a different type of war is being raged. It is from this location that an elite group of codebreakers is attempting to do the impossible, break the German Enigma code.
The story of the codebreakers at Bletchley Park is one of the most thrilling of the entire war. While soldiers across the world were busy waging battles with fighter planes, mortars and BARs, the men and women of Bletchley Park were fighting a war armed only with their outstanding intellect. While far less flashy, these minds came together to save millions of lives and shorten the course of the deadliest war in human history. They are truly some of the forgotten heroes of the entire conflict.
Continue reading to discover the story of the codebreakers of Bletchley Park as well as the top tips for visiting this historic location.
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What was Bletchley Park?
Located in the town of Milton Keynes, Bletchley Park was originally owned by Samuel Seckham. In 1883, the property was purchased by Herbert Leon, who went on to expand the home into the mansion we see today. The Leon family occupied the home until 1937. In 1938 the mansion and a surrounding 58 acres were purchased by head of MI6, Hugh Sinclair. Bletchley Park was about to occupy an immortal role in the history of wartime intelligence.
The War Years
Following its purchase by the British government, Bletchley Park was officially designated Station X and assigned as the Government Code and Cypher School. The first workers began arriving at the site in 1939. In the early days, Bletchley was home to about 200 workers. By the end of the war, the workforce had grown to nearly 10,000.
Though they came from different countries, social standings and academic backgrounds, the role of the codebreakers was largely the same, to intercept, analyze and decrypt coded messages from enemy militaries. The work was long and difficult as the ciphers used by these various militaries were intricate and largely considered “unbreakable.”
The workday was divided into eight-hour shifts six days a week, with work continuing around the clock throughout the war years. The workers slept, ate and socialized within the grounds of Bletchley Park. They were granted very little down time and leave was almost non-existent. The work they were doing was too important to the war effort to allow time away. Because of this, fatigue and burnout became very real factors. The pressure cooker of living and working under extreme secrecy was a heavy burden, but the critical work had to continue. Lives were at stake.
Looking for more WWII locations to add to your travel bucket list? Check out The Ultimate Guide to WWII Sites in Europe.
Post-War Operations
Codebreaking operations continued at Bletchley Park until 1946. For the next 40 years, the site served as a training ground for everything from school teachers to postal service workers. The last training school was shut down in 1987 and the site was left to fall into a state of disrepair. By the early 1990s, a proposal was in place to demolish the entire site into order to make way for housing developments.
In 1992, a local committee stepped in to prevent one of England’s most important WWII sites from being demolished. Bletchley Park was officially designated a conservation area. The site opened as a museum in 1993 and has been welcoming visitor’s to discover the heroic story of the WWII codebreakers ever since. Bletchley Park is an amazing example of an important historical site that was almost lost to progress, only to be miraculously preserved for generations to come.
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How did the Codebreakers Help Win the War?
Intelligence gathering and codebreaking have been an important component of warfare since the beginning of armed conflict. The technology and methods have changed throughout the centuries, but the value in learning your opponent’s next move before they can strike has never diminished. This same line of thinking was applied to the work done at Bletchley Park. The goal is simple, learn everything you can about the enemy by deciphering their coded messages as quickly as you can in order to properly prepare your own forces against them.
The codebreakers at Bletchley Park worked to achieve this mission by deciphering codes from every Axis power. They proved to be very successful at this task. Throughout the course of the war, several key ciphers used by the Japanese, Germans, and Italians were broken. While the codebreakers were not able to break every major cipher system, they were able to gain enough intelligence to significantly impact the course of the war. In fact, experts believe that the work done at Bletchley Park helped shorten the war by two years and save an estimated 14 million lives.
The Enigma Machine and the Bombes
As German forces begin their sweep across the continent, encrypted messages were constantly being sent across all branches of military command. These messages relayed valuable information ranging from troop positions to supply movements. They were delivered with the utmost confidence that their contents would remain indecipherable to anyone apart from their intended receiver due to one of the most powerful weapons in the German arsenal, the Enigma machine.
The Enigma was developed after WWI as a cipher device, designed to encrypt messages. The machine was so advanced that the commonly held belief was that it would be impossible to break its code. The machine worked by scrambling each individual letter through a series of rotors which changed with every new typed letter. Because of the frequency of changes and settings on the machine which were changed daily, the Enigma could configure letters in a quintillion different ways, making the task of deciphering it nearly impossible.
Thankfully, the codebreakers at Bletchley Park were up to the task. Building upon the work of Polish mathematicians, Alan Turing and other cryptanalysts designed the Bombe, a machine which replicated the actions of several Enigma machines working in unison. The Bombe was able to test different pathways the Enigma could take and eliminate incorrect paths on a daily basis. Eventually the machine was able to decipher the majority of Enigma messages within a matter of minutes, providing the Allies with key intelligence to be used against the Germans.
For information on another unique WWII site near London, check out The Battle of Britain Bunker.
Who Were the Codebreakers?
Codebreakers were brought in from every corner of Great Britain. They were selected based on their cognitive and reasoning skills. Many of them showed a high aptitude for crossword puzzles and chess. They were scientists, engineers and mathematicians. They were highly intelligent and capable of viewing problems through a unique lens. The workforce was largely made up of women, many of whom were members of the Women’s Royal Naval Service, known as “Wrens.”
It is no exaggeration to say that the codebreakers who worked at Bletchley Park changed the world. In addition to their work in breaking the codes which helped shorten the war, they were the forebears of many of our modern technologies including the world’s first digital computer. While every codebreaker who worked at Bletchley Park was remarkable in his or her own way, I have highlighted a few of the most well-known below.
Alan Turing
Alan Turing arrived at Bletchley Park in 1939 and stayed throughout the end of the war. He was a brilliant mathematician who used his skills to develop the Bombe, the device used to test the daily Enigma key settings. Turing is often referred to as the father of theoretical computer science. His work helped lay the foundation for the modern computer and his thoughts on artificial intelligence are still widely regarded today.
Joan Clarke
Despite the fact that about 75% of all workers at Bletchley Park were female, the women codebreakers often fail to receive the same recognition as their male counterparts. Joan Clarke was a mathematician when she arrived at Bletchley Park, a rare field of work for women at the time. She worked closely with Turing and others to crack the Enigma cipher. She became the first female practitioner of Banburisms, a process which helped decipher naval Enigma messages. She remained at Bletchley Park until it ceased operations in 1946.
Gordon Welchman
Gordon Welchman was another mathematician employed at Bletchley Park. He was one of the first workers to arrive at the site. He was also instrumental in breaking the Enigma cipher, though he worked largely on the German air force ciphers. He contributed the “diagonal board” to the Bombe, which helped make the machine more powerful and accurate. After the end of the war, Welchman immigrated to the United States where he continued his work in military intelligence.
If you have more time in London, be sure to check out the Top WWII Sites in London.
Visiting Bletchley Park Today
Bletchley Park is must-visit for anyone interested in learning more about WWII history in England. It is a short train ride from central London, making it a fantastic daytrip. The site is relatively compact and easily explored within a couple of hours. Consider a visit to this historic site to honor those men and women who worked in absolute secrecy to secure an Allied victory.
Basic Information
Opening Hours: 9:30 – 5:00 (March 1 to October 31) 9:30 – 4:00 (November 1 to February 28), last admission 2 hours before closing
Tickets: £25.87 (advance booking) £28.75 (at the gate)
Dining: Hut 4 Café and Block C Coffee Shop
Website: Bletchley Park
Exploring Bletchley Park
A visit to Bletchley Park is a rewarding and fascinating experience. Many of the original buildings, including the Mansion, have been preserved and are open to visitors. The site is well signed and easily explored on your own. However, the museum does offer daily tours which are included with your admission ticket. To help you prepare for your visit, I have provided a brief description of the main sides of Bletchley Park.
The Mansion
The Mansion is the original homesite at Bletchley Park. The home dates to the late 19th century. During the war years, it served as the original lodging and workplace of the earliest codebreakers. As the workforce expanded, its purpose shifted to house offices and leisure rooms.
Huts 3 and 6
These huts were restored to match their appearance during the war. Workers within these huts translated and analyzed decrypted messages from the German Enigma machine. As you walk through these areas, pay attention to the sites and sounds. The space is designed to make you feel like you are in a room of codebreakers during the 1940s.
Hut 8
Hut 8 helps visitors understand the various methods used by the codebreakers, specifically when it comes to decoding German naval messages. It is also home to Alan Turing’s office.
Huts 11 and 11A
Step into these huts to gain a better understanding of the Bombes, the machines created to break the Enigma code. The rooms include exhibits which help explain how the Bombes work as well as examples of the machines in action.
Block B
Block B houses a museum dedicated to many aspects of codebreaking. It includes displays on the breaking of the Lorenz cipher and the Enigma machine as well as a special section dedicated to the life of Alan Turing.
For another WWII site in England, consider a visit to Dover Castle and the Secret Wartime Tunnels.
Honoring the Memory of the Codebreakers
The codebreakers who worked at Bletchley Park and other secret intelligence gathering facilities across the Allied world are truly some of the most unsung heroes of the war. Their work, by its very nature, was conducted in complete secrecy, ensuring that the outside world was unable to honor them the way they deserved. If you are able, consider a visit to Bletchley Park. This historic site will not only teach you a great deal about the ins and outs of codebreaking, but it will also give you the chance to honor the memory of the remarkable men and women who helped win the war.
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