Colossus was the world's first electronic programmable computer at Bletchley Park in Buckinghamshire. Bletchley Park was the British forces' intelligence centre during WWII, and is where cryptographers deciphered top-secret military communiques between Hitler and his armed forces. The communiques were encrypted in the Lorenz code which the Germans considered unbreakable, but the codebreakers at Bletchley cracked the code with the help of Colossus, and so aided the Allies' victory. The women seen here belonged to the Women's Royal Naval Service, (WRNS) and were nicknamed 'Wrens'.
© Bletchley Park Trust / Science & Society Picture Library