Dilly Knox facts for kids

Alfred Dillwyn "Dilly" Knox (23 July 1884 – 27 February 1943) was a brilliant British scholar and codebreaker. He studied classics at King's College, Cambridge. During the First World War, he was part of the secret Room 40 codebreaking team. He helped crack the Zimmermann Telegram, a message that played a big part in bringing the USA into the war.

Later, Dilly joined the Government Code and Cypher School (GC&CS). Before the Second World War, he was a key figure in meetings where Poland shared its secret knowledge of the Enigma machine with Allied countries. At Bletchley Park, the famous codebreaking center, he led efforts to break Enigma codes until his death in 1943. His team successfully broke the Italian Naval Enigma, which helped the Allies win the Battle of Cape Matapan. In 1941, Knox also broke the German Abwehr Enigma. His work provided vital information for important events like D-Day.

Dilly Knox: Early Life and Family

Dillwyn Knox, known as "Dilly," was the fourth of six children. His father, Edmund Knox, was a tutor and later a Bishop. Dilly had several siblings who also became well-known, including E. V. Knox, Wilfred Knox, Ronald Knox, and Winifred Peck. He was also the uncle of the famous novelist Penelope Fitzgerald.

Dilly went to Summer Fields School and then Eton College. In 1903, he began studying classics at King's College, Cambridge. He became a Fellow there in 1909. While at university, he was friends with Lytton Strachey and John Maynard Keynes. For a few weeks in 1910, he even tutored Harold Macmillan, who later became the Prime Minister of the United Kingdom.

In 1920, Dilly married Olive Rodman. They had two sons, Oliver and Christopher.

Dilly Knox: Academic Work

Between the two World Wars, Dilly Knox focused on a large academic project. He worked on a detailed study of the ancient Greek writer Herodas. This project had been started by Walter Headlam. Dilly spent many hours studying old papyrus fragments from the British Museum. This intense work even damaged his eyesight. However, he successfully managed to read and understand the difficult texts. The finished book, the Knox-Headlam edition of Herodas, was published in 1922.

Dilly Knox: Codebreaking Secrets

First World War Codebreaking

When the First World War began in 1914, Dilly Knox was asked to join the Royal Navy's secret codebreaking team. This team worked in a place called Room 40 at the Admiralty building. It's said that he even had a bathtub in his office, where he sometimes did his work! In 1917, Room 40 expanded into a new section called ID25.

Dilly was involved in breaking many important German codes. One of his most famous achievements was helping to decrypt the Zimmermann Telegram. This secret message was a big reason why the USA joined the war. He also helped break a German admiral's flag code. He did this by noticing that the German operator liked to use romantic poetry in his messages.

Between the Wars: Secret Work Continues

After the First World War, Dilly Knox had planned to go back to his academic research. However, his wife convinced him to continue his secret codebreaking work. His job was so secret that his own children didn't know what he did for a living until many years after he died. They had no idea about his huge contribution to the war effort.

Cracking the Commercial Enigma

The Enigma machine was a device used to encrypt messages. It became available for sale to businesses in the 1920s. In 1925, Dilly Knox bought one of these Enigma machines in Vienna. Another codebreaker, Hugh Foss, studied it and found it was very secure. However, Foss wrote a secret paper explaining how to attack the machine if you could guess small parts of the plain text message, called "cribs." Ten years later, Dilly Knox picked up this work. He developed a more effective method called "rodding," which was based on Foss's ideas.

Solving the Spanish Enigma

In 1926, the German Navy started using the Enigma machine. They added a "plug-board" (called stecker in German) to make it even more secure. During the Spanish Civil War, Nazi Germany supplied Enigma machines without plug-boards to Francisco Franco's forces. On 24 April 1937, Dilly Knox successfully broke the Spanish Enigma code. His discoveries were kept secret. Soon after, Knox began to work on messages between Spain and Germany that were encrypted using the more complex plug-board Enigma machines.

Preparing for World War II

Meetings with Polish Codebreakers

In 1938, the British codebreaking team (GC&CS) began talking with the French about the Enigma machine. The French shared information they had received about the German army's Enigma. This led the French to reveal their secret connection with the Polish codebreakers, known as the Biuro Szyfrów.

Dilly Knox, along with Hugh Foss and Alastair Denniston, represented Britain at the first meeting in Paris in January 1939. The Polish team was ordered not to share anything too important, which left the British codebreakers disappointed. However, Knox's explanation of his "rodding" system impressed the Poles. They asked him to attend a second meeting.

Marian Rejewski, a Polish codebreaker, later said that Knox understood everything very quickly. He realized that the British had been working hard on Enigma.

Knox attended the second secret meeting on 25-26 July 1939, in Poland. This time, the Poles began to share their amazing achievements in solving the Enigma machine's secrets with their French and British allies.

Rejewski, a mathematician, had solved the plug-board Enigma using complex math. Knox, on the other hand, used a language-based approach. Despite their different methods, they quickly formed a good relationship. Knox was surprised but grateful to learn how simple the solution to one part of the Enigma was.

After the meeting, Dilly Knox sent a kind note in Polish to the Polish codebreakers. He thanked them for their help and patience. He also sent them a beautiful scarf and a set of paper "batons." These "batons" were what the British called "rods," and they had been used to solve the Spanish Enigma. Knox's rodding method would later be used to break the Italian Naval Enigma.

Turing's Bombe Machine

Alan Turing, another brilliant mathematician, also worked on the Enigma machine before the Second World War started in September 1939. He sometimes visited GC&CS in London to discuss the problem with Dilly Knox. In November 1939, Turing finished designing the "bombe." This was a much-improved version of a machine the Poles had created, and it was crucial for breaking Enigma codes.

Second World War: Breaking More Codes

Knox's Rodding Method in Action

To break Enigma machines that didn't have a plug-board, Dilly Knox used his "rodding" system. This method was based on language patterns, not complex math. It worked well on the Enigma machines used by the Italian Navy (Regia Marina) and the German spy agency (Abwehr). Knox worked in a building called 'the Cottage' at Bletchley Park. He led a research section that made big contributions to breaking Enigma codes.

Knox's team at 'the Cottage' used rodding to decrypt Italian naval messages. These messages described the movements of an Italian battle fleet. This vital information led to the Battle of Cape Matapan in March 1941. Admiral John Godfrey, the Director of Naval Intelligence, said that this intelligence was key to the Allied victory at Matapan. Admiral Sir Andrew Cunningham, who commanded the winning fleet, even visited Bletchley Park to congratulate "Dilly and his girls" – the female codebreakers who worked with him.

Intelligence Services Knox

In October 1941, Dilly Knox successfully broke the German Abwehr Enigma. A special unit called Intelligence Services Knox (ISK) was then set up to decrypt Abwehr messages. In early 1942, Dilly Knox became very ill. Peter Twinn took over running ISK and became its head after Knox's death. By the end of the war, ISK had decrypted and shared 140,800 messages. The information from these Abwehr decrypts was very important. It helped ensure the success of the Double-Cross System, which tricked the Germans. It also played a big part in Operation Fortitude, a plan to deceive the Germans about where D-Day would happen.

Dilly Knox's Death

Dilly Knox's important work was cut short when he became ill with lymphoma, a type of cancer. When he could no longer travel to Bletchley Park, he continued his codebreaking work from his home in Hughenden Valley. He was awarded the CMG for his service. Dilly Knox passed away on 27 February 1943. A book about his life, written by Mavis Batey, one of the "Dilly's girls" who worked with him, was published in 2009.

Dilly Knox: Secret Poetry

Dilly Knox celebrated the Allied victory at the Battle of Cape Matapan by writing a poem. This poem remained a secret until 1978.