Colossus: Britain's secret code-breaking computer that helped win World War II

Previously unreleased images of the secret British code-breaking computer 'Colossus', credited with playing a key role in the Allied victory in World War II, have been released by GCHQ.

80th anniversary

The intelligence agency is releasing these photos to commemorate the 80th anniversary of the device's invention. GCHQ says these photos "shed new light on the origins and operating principles of Colossus."

Colossus' History

The Colossus is considered by many to be the first digital computer. Its existence was largely kept secret until the early 2000s.GCHQ director-general Anne Kist-Butler said the photos were a reminder of the "creativity and ingenuity" needed to keep the country safe.

Colossus’ technological innovations

“Technological innovation is at the core of our work at GCHQ and Colossus is a perfect example of how our people keep us at the forefront of new technologies – even when we can’t talk about it,” she said.

Colossus' Success

By the end of the war, 10 computers helped decipher Nazi messages. These computers were equipped with 2,500 valves and stood more than 2 meters tall.Operating and maintaining the Colossus required a team of skilled operators and technicians, often members of the Women's Royal Naval Service (Wrens).