Bringing Colossus back to life

Pictured with the revamped machine is Tony Sale, who led the 14-year Colossus rebuild project.

Colossus was originally designed by a group at Bletchley Park which included engineer Tommy Flowers and mathematician Max Newman.

The prototype, Colossus Mark I, arrived at Bletchley in December 1943 and was operational by February 1944.

An improved Colossus Mark II was first installed in June 1944 and was working in time for Eisenhower and Montgomery to be sure Hitler had swallowed the deception campaigns prior to the D-Day landings on 6 June, 1944.

There were eventually 10 working Colossi at Bletchley.

Credit: National Museum of Computing