Alfred Dillwyn "Dilly" Knox, CMG (23 July 1884 – 27 February 1943) was a British classics scholar and papyrologist at King's College, Cambridge and a codebreaker. As a member of the Room 40 codebreaking unit he helped decrypt the Zimmermann Telegram which brought the USA into the First World War. He then joined the Government Code and Cypher School (GC&CS). As Chief Cryptographer, Knox played an important role in the Polish-French-British meetings on the eve of the Second World War which disclosed Polish cryptanalysis of the Axis Enigma to the Allies. At Bletchley Park he worked on the cryptanalysis of Enigma ciphers until his death in 1943. He built the team and discovered the method that broke the Italian Naval Enigma, producing the intelligence credited with Allied victory at the Battle of Cape Matapan. In 1941 Knox broke the Abwehr Enigma. By the end of the war, Intelligence Service Knox had disseminated 140,800 Abwehr decrypts, including intelligence important for D-Day. Personal life and family Dillwyn Knox, the fourth of six children, was the son of Edmund Knox, tutor at Merton College and later Bishop of Manchester; he was the brother of E. V. Knox, Wilfred Knox, Ronald Knox, Ethel Knox, and Winifred Peck, and uncle of the novelist Penelope Fitzgerald. His father was a descendant of John Arbuthnott, 8th Viscount of Arbuthnott. Dillwyn—known as "Dilly"—Knox was educated at Summer Fields School, Oxford, and then Eton College. He studied classics at King's College, Cambridge from 1903, and in 1909 was elected a Fellow following the death of Walter Headlam, from whom he inherited extensive research into the works of Herodas. While an undergraduate he was friends with Lytton Strachey and John Maynard Keynes. He and Keynes were lovers at Eton. Knox privately coached Harold Macmillan, the future Prime Minister at King's for a few weeks in 1910, but Macmillan found him "austere and uncongenial". He married Olive Rodman in 1920, forgetting to invite two of his three brothers to his wedding. The couple had two sons, Oliver and Christopher. He was an atheist. Academic scholarship Between the two World Wars Knox worked on the great commentary on Herodas that had been started by Walter Headlam, damaging his eyesight while studying the British Museum's collection of papyrus fragments, but finally managing to decipher the text of the Herodas papyri. The Knox-Headlam edition of Herodas finally appeared in 1922. Codebreaking First World War