Today in 1943, the prototype of the Mark 1, the world’s first electronic computer, was successfully tested at Dollis Hill, United Kingdom.
It was taken apart and shipped to Bletchley Park, where it was delivered and re-assembled on January 18, 1944. As it was a large structure, it was quickly dubbed Colossus by its operators, who used it and the subsequent improved models to obtain a vast amount of high-level military intelligence from radiotelegraphy messages sent between the German High Command and their army commands throughout occupied Europe.
By the end of the war, 63 million characters of high-grade German communications had been decrypted by 550 people helped by the ten Colossus computers. Not until 1975 when the first information about Colossus was declassified could the story begin to be told.
In 2007, a replica of a Colossus computer was completed and put on display at the National Museum of Computing at Bletchley Park.