by Gethin Thomas October. 21, 2020 240 views

These photos were taken on two separate occasions. First in 2008 before the buildings had been restored and the museum built, then in 2016 after many years of restoration.

Bletchley Park is an English country house and estate in Milton Keynes that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following 1883 for the financier and politician Sir Herbert Leon in the Victorian Gothic, Tudor, and Dutch Baroque styles, on the site of older buildings of the same name.

During World War II, the estate housed the Government Code and Cypher School (GC&CS), which regularly penetrated the secret communications of the Axis Powers – most importantly the German Enigma and Lorenz ciphers; among its most notable early personnel the GC&CS team of codebreakers included Alan Turing, Gordon Welchman, Hugh Alexander, Bill Tutte, and Stuart Milner-Barry. The nature of the work there was secret until many years after the war.

More recently, Bletchley Park has been open to the public and houses interpretive exhibits and rebuilt huts as they would have appeared during their wartime operations. The separate National Museum of Computing, which includes a working replica Bombe machine and a rebuilt Colossus computer, is housed in Block H on the site.

Alan Mathison Turing OBE FRS was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. Turing is widely considered to be the father of theoretical computer science and artificial intelligence.

A statue of Alan Turing, created in slate by Stephen Kettle in 2007, is located at Bletchley Park in England as part of an exhibition that honours Turing (1912–1954). It was commissioned by the American businessman and philanthropist Sidney Frank (1919–2006).

The slate for the sculpture was selected from North Wales because the sculptor learned that Turing used to holiday there as a child and adult. The slate originated from Llechwedd, near Blaenau Ffestiniog. Turing is depicted seated and looking at a German Enigma machine. He is dressed in a jacket, but there is some deliberate untidiness in his clothing.

The site, unrestored in 2006.

The site appears in the Domesday Book as part of the Manor of Eaton. It was first known as Bletchley Park after its purchase by Samuel Lipscomb Seckham in 1877. The estate of 581 acres (235 ha) was bought in 1883 by Sir Herbert Samuel Leon, who expanded the then-existing farmhouse into what architect Landis Gores called a "maudlin and monstrous pile" combining Victorian Gothic, Tudor, and Dutch Baroque styles. At his Christmas family gatherings there was a fox hunting meet on Boxing Day with glasses of sloe gin from the butler, and the house was always "humming with servants". With 40 gardeners, a flower bed of yellow daffodils could become a sea of red tulips overnight.

In 1941 Agatha Christie penned a novel called N or M? In it there appeared an old army officer called Major Bletchley, but at the time only the people working at the Park or at the War Office officially knew the location. One of Christie's close friends was the codebreaker Dilly Knox and MI5 (alarmed that there had been a breach of security) interviewed Knox to condemn him for spilling the secret to Christie, but he maintained that he had not. Knox then invited Christie around for tea to try and straighten out the situation. On asking why she had named the army character Bletchley she replied "Bletchley? My dear, I was stuck there on my way by train from Oxford to London and took revenge by giving the name to one of my least lovable characters." MI5 were relieved and dropped the issue. (

The Mansion is one of the most iconic buildings on site. It is where the first Codebreakers were based before the workforce expanded into newly built huts, and later purpose-built brick and concrete blocks. Today you can explore a number of temporary and permanent exhibitions here including:

The Office of Alastair Denniston, Head of the Government Code and Cypher School, and the room where the US-UK Special Relationship was born.

The Library, atmospherically dressed as it would have looked as a Naval Intelligence office during WW2.

One interesting fact on secrecy. D Day was probably the best kept secret in human history. When you consider how many hundreds of thousands of individuals were involved it is astonishing that it was kept under wraps. This was achieved on a need to know basis, so put simply, everyone who played a part, only knew what they needed to know to play their part. The actual date of D-Day was only revealed to those concerned on the day it happened.

The only problem was, after telling everyone, they changed the date by a day. It was thought the weather would be better on June 6th than it would be on June 5th, which was the original day planned. Problem, too many people now know the secret, what do you do? Simple, nobody leaves the building for 24 hours. Everyone who had been told was quarantined for a day. Everyone at Bletchley Park was confined to their huts and not allowed to leave. D Day was saved.

(below)Modified Army and Air-Force Enigma-A16991.

The plugs have been removed from the plugboard as part of this alteration and modified to include the addition of a small plug board on the left side of the case. This modification probably undertaken by Bletchley Park.

The Museum in Block B. This original wartime building, built in 1942, is now where you can explore fascinating exhibitions about the work and people of Bletchley Park. This includes:

The Life and Works of Alan Turing gallery.

Hitler’s “Unbreakable” Cipher Machine: Gallery dedicated to telling the story of the breaking of the Lorenz cipher

The largest and most comprehensive public display of Enigma machines in the world.

(below) Lorenz Schlusselzusatz SZ 40

by the Lorenz Company, these machines were used for the most important messages between Field Marshalls and Generals at the front lines and Central High Command. Intercepted enciphered messages from these machines were codenamed "tunny" by Bletchley Park. In 1945 von Kesselring's communications vehicle was captured in Italy along with his Lorenz machines. This device was sent to Bletchley Park for investigation. von Kesselring was overall commander of operations for the Mediterranean and North Africa.

(below) The Bombe

The British bombe was developed from a device known as the "bomba" (Polish: bomba kryptologiczna), which had been designed in Poland at the Biuro Szyfrów (Cipher Bureau) by cryptologist Marian Rejewski, who had been breaking German Enigma messages for the previous seven years, using it and earlier machines. The initial design of the British bombe was produced in 1939 at the UK Government Code and Cypher School (GC&CS) at Bletchley Park by Alan Turing, with an important refinement devised in 1940 by Gordon Welchman.

This sentry box guarded the site's back gates. Motorcycle Dispatch Riders would arrive at these gates day and night carrying intercepted enemy messages from Y Stations. Secret communications to and from London and military bases around the UK were also taken by car and motorcycle through this entrance.

One of the restored huts on the site. All workers at the site were confined to one element of the codebreaking process. Secrecy was so great that no ordinary staff member knew what went on in any other hut. You never discussed what you did with anyone. This meant very few individuals had a full picture of what was going on. As many as ten thousand people were working for Bletchley Park at the time. It is remarkable that as far as is known not a single secret ever left the base. It is even more remarkable that all of those people never spoke about it for decades after the war. This was a secret, probably one of only a few that remained so, long after World War 2 and well into the Cold War as it remained relevant into that era.

How did they recruit the people they needed to break the codes? Sep 22 1942, The Cryptic Crossword that Recruited for Bletchley Park.

In 1942 the Telegraph newspaper had been receiving letters complaining that the cryptic crosswords they had been publishing were too easy and that they could be solved in a few minutes. The editor thought that this couldn't be true and so arranged to have a time challenge: to solve the crossword in 12 minutes under test conditions. Many people came along and five finished in the time allotted. The next day the crossword was published in the paper so that the general public could try their own wits against the timed puzzle.

Recruitment for a position in an organisation that had to remain a secret was necessarily difficult. However the war office were looking in on the test and a few weeks after the event each of the fastest solvers received a letter inviting them to work at Bletchley. (

This tape below was placed over windows to prevent flying glass in the event of bombing. But Bletchley Park was never bombed. Why?

Officially it was a radio factory. Even that, you would have thought would warrant an attack. But it is thought that cities and major newsworthy attacks like Coventry Cathedral would be more effective in grinding down morale. Goering did not prioritise communications targets and they underestimated how important that was and how the RAF depended on communication. It is hard to believe that now, but there was a certain arrogance involved in the higher echelons of the Nazi party that meant they underestimated many actions the Allied forces were engaged in. They were aware codes could be broken which was why they continually evolved the Enigma machines throughout the war. What they massively underestimated was what lengths Britain would go to to get complete control of German communications. Most of the Germans involved in Enigma were dumbfounded after the war at how much resource was invested by Britain into cracking the codes. The scale of the Bletchley Project was inconceivable to them.

(below) Modified Enigma - M16264

Modified to contain 27 mechanical digital counters. The original German keyboard has been replaced by a standard QWERTY one. The modification was probably made by Bletchley Park to undertake statistical character analysis within messages.

(below) Naval M4 Enigma-M584G

This machine was developed during the war exclusively for the U-Boat division of the German Navy. This type uses four rotors, chosen from a set of eight.

(below) Naval Enigma - M1322

The plugboard carries both A-Z and 1-26 markings.

(below) Alan Turing's Teddy Bear

This Chad Valley Co. Ltd. Teddy bear was purchased by Turing as an adult and named "Porgy". Alan had a whimsical sense of humour and at Cambridge is reputed to have practised his lectures with Porgy as the audience.

The clothes were made by Turing's sister-in-law and Porgy still wears them 77 years later.

After the war Turing worked at the National Physical Laboratory, where he designed the Automatic Computing Engine. The Automatic Computing Engine was one of the first designs for a stored-program computer. In 1948, Turing joined Max Newman's Computing Machine Laboratory, at the Victoria University of Manchester, where he helped develop the Manchester computers and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis and predicted oscillating chemical reactions such as the Belousov–Zhabotinsky reaction, first observed in the 1960s.

In December 1951, Turing who was gay met a man with whom he had a very short relationship which ended with Turing's home being burglarised. In reporting this crime to the police Turing made a statement which implicated him in the far more serious crime of gross indecency which was not decriminalised until 1967. As a result Turing was charged, tried, and found guilty, and opted for chemical castration a barbaric practice offered at the time as an alternative to a prison sentence.

Turing now became a security risk. All that is known for certain is that he died from cyanide poisoning from a tainted apple. There has been much speculation ever since as to whether it was suicide, accidental or a murder by persons unknown. It is believed Turing did work with cyanide which was why that was considered as a possibility although it is doubtful.

The truth is that we will probably never know.

In 2009, The Prime Minister Gordon Brown issued an unequivocal apology from the British Government to Alan Turing 55 years after his death.

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There are 2 comments , add yours!
Brian Scott 1 month, 1 week ago

Fabulous blog Gethin,I'd love to have +1 explored the site before restoration.

1 month, 1 week ago Edited
Camellia Staab 1 month, 1 week ago

Very interesting information and photos. Several movies and series were made of the code breakers and Bletchley Park, my favorite was the British series  The Bletchley Circle. Also your photos reminded me of  Churchill's War Room in London some very cool captures.

1 month, 1 week ago Edited