Colossus was one of the earliest computers ever built, and was constructed by the codebreakers at Bletchley Park in the UK during the second world war. Its purpose was to assist in the effort to break the Axis "fish" communication code, a feat which was eventually accomplished, and which probably shortened the war by a considerable length of time. Its 1800 vacuum tubes were assembled in less than a year, and though it was not as flexible as later programmable computers, its ability to process a variety of cryptographic routines made it one of the first functional digital electronic computers. One of the principal scientists involved in its contruction was the great mathematician and computer scientist, Alan Turing.