Peter Twinn

Peter Frank George Twinn was a British mathematician recruited by the Government Code and Cypher School before the Second World War. At Bletchley Park he worked first with Dilly Knox and then alongside Alan Turing.

Enigma work

Bletchley Park records credit Twinn with the first British break into a German Enigma intercept in July 1939. He contributed to Bombe development, worked in Hut 8, and later led the ISK section’s work against Abwehr Enigma traffic.

Public service and legacy

After the war he held senior roles in the British scientific civil service. His career illustrates how cryptanalytic progress moved between theory, machinery, and organized intelligence work.

In memoriam

Twinn died in 2004, aged 88. His carefully documented contribution to Enigma cryptanalysis remains part of Bletchley Park’s history.

Timeline

• 1916-01-09Born in London, England.
• 1939Recruited to the Government Code and Cypher School.
• 1939-07Makes the first British break into a German Enigma intercept.
• 1942Takes over the ISK section after Dilly Knox’s illness and death.
• 2004-10-29Dies in England.