  F.H. Hinsley, official historian of GC&amp;CS, has estimated that the war in Europe was shortened by at least two years as a result of the signals intelligence operation carried out at Bletchley Park, in which Colossus played a major role. Most of the Colossi were destroyed once hostilities ceased. Some of the electronic panels ended up at Newman's Computing Machine Laboratory in Manchester (see below), all trace of their original use having been removed. Two Colossi were retained by GC&amp;CS (renamed GCHQ following the end of the war). The last Colossus is believed to have stopped running in 1960.