The May speaker was Dr P Jarvis, a trustee of Bletchley Park Trust.

He stressed the importance the park played in the Second World War when a team comprising three chess grand masters and leading crossword setters succeeded in cracking the German's Enigma Code which played a vital role in the war effort.

Dr Jarvis outlined the development of codes and ciphers, the latter being used in the time of Julius Caesar. He said how important the use of code books was, but there was always the risk of the code being broken.

The Bayeux Tapestry is a form of cipher and Mary Queen of Scots used ciphers, which led to her execution.

Around 12,000 people worked at Bletchley Park and the Germans never realised their codes had been broken.

Details of this local group can be obtained from the secretary, Marjorie Fernihough, on 01562 883460.