When was the Colossus computer built?

The actual computers called Colossus were World War II code-breaking computers built in 1943 and 1944 in Bletchley Park, Buckinghamshire, England. These were the first true programmable computers, and about a dozen were built.

The prototype, Colossus Mark I, was shown working in December 1943 and was operational at Bletchley Park by February 1944. An improved Colossus Mark II was first installed in June 1944, and ten more had been constructed by the end of the war. Unfortunately, the secret nature of these computers meant that their innovations were not available for commercial computer development for many years.

*The other computer called Colossus is a fictional artificial intelligence from a 1965 novel (Colossus) by Dennis Feltham Jones, which was the basis for the film Colossus, the Forbin Project in 1970