Mike’s talk provides the history of the Government Code and Cypher School from its creation in 1919 through its evolution into the Bletchley Park codebreaking and intelligence factory through World War II. The technical challenges of the Enigma and Lorenze ciphering machines and the solutions generated by the Allied Codebreakers including the Turing Bombe and Colossus Computer are explained. Mike has been a volunteer at Bletchley Park for over eleven years. His presentation talks about the realities of working at Bletchley Park