History Features

The codebreakers of Bletchley Park are to be honoured, 64 years after the end of the Second World War.

The surviving veterans will be given commemorative badges next week, because as many were civilians, they cannot be given military service medals.

World War II buildings at Bletchley Park

During the Second World War, 12,000 people, a mixture of military and civilians, worked intercepting and deciphering encoded messages being sent by the enemy, using the very machine the Germans used to encrypt it and believed was impregnable - Enigma.

The staff were chosen for their mathematical and linguistic prowess but many had little knowledge about the exact nature of their work.

Codebreakers were helped by Polish mathematicians who had managed to acquire an Enigma machine before the war.

To speed up the codebreaking process, mathematician Alan Turing developed an idea originally proposed by Polish cryptanalysts. The result was the Bombe, an electro-mechanical machine that greatly reduced the odds, and thereby the time required, to break the daily-changing Enigma keys.

Until now, the codebreakers have never received official recognition for what they did. Their top secret work remained top secret until the 1970s and is credited by historians with shortening the war by at least two years and saving thousands of lives. Churchill called the codebreakers the geese that laid the golden egg.

Jean Valentine with the Bombe in more re

Tony Sale, who's rebuilt the Colossus machine, the world's first computer, says even though the hours were hard and the work was often dull, the codebreakers' commitment never wavered.

“Everybody knew they were contributing to the war effort” he said.

“Deniston and Travers, the leaders of the people here, were excellent person managers and so they got these teams together and got them motivated to do this very, very boring work but everybody knew how important it was.”

Find out more:

A tour of Bletchley Park

Bletchley Park Veterans

The Colossus Machine

Tony Sale, who rebuilt Colossus, the world's first computer which was invented at Bletchley Park during the Second World War, explains how tricky it was for the codebreakers not to let the Germans know they were reading all their messages. After the initial German mistake which sped up the process, it could all have come to a grinding halt ...

The Bombe Machine

The Bombe Machine was used to find the daily settings being used by the Germans on the Enigma machine. It ran through the possible combinations which numbered 158 million, million, million. Once the settings had been established, the codebreakers could then decipher the messages for the 24-hour period that those settings had been used. By the end of the war there were 210 bombe machines, not all at Bletchley Park. The basic concept was developed at Bletchley but the engineering was done in Letchworth. John Harper is a retired engineer and one of the group of very clever volunteers who've rebuilt the machine, from drawings handed over by GCHQ, photographs taken at Bletchley Park and the memories of veterans who worked on the machines.... here he explains it all!

Simon Greenish

The director of Bletchley Park, Simon Greenish, gives us a beginner's guide to the Enigma machine and explains how the importance of what the codebreakers did cannot be underestimated.