IMAGES OF THE NATIONAL ARCHIVES: Codebreakers

The centre of Britain's codebreaking operation was located at Bletchley Park where a hastily assembled army of codebreakers battled to decipher Germany's secret wartime communications. A motley collection of linguists, mathematicians and crossword enthusiasts pitted their combined wits against the 'unbreakable' naval Enigma codes and Lorenz ciphers used by Hitler and the German High Command. They deciphered high-level signals intelligence disseminated to military commanders was known as Ultra, and had a major influence on the outcome of the war and success in the battle for the Atlantic. British interest in codes and ciphers stretches back to the court of Elizabeth I and her spymaster Sir Francis Walsingham. The book traces the history of the school established by him in the 1570s to the work of the Secret Office of the Post Office in the 18th century to the creation of the Government Code and Cipher School in 1919. The exploits of the two World Wars form a major aspect of the story and include the achievements of the Admiralty's Room 40 and the infamous Zimmermann Telegram, the contribution made by Alan Turing and his ground-breaking work into computing, and a brief overview of post-war developments and the importance of signals intelligence in the Cold War. 132 page extra large softback, many illus.