Post Office Research Station

The Post Office Research Station at Dollis Hill, London, was first established in 1925 and opened by Prime Minister Ramsay MacDonald in 1933.In 1943 the world's first programmable electronic computer, Colossus Mark 1 was built by Tommy Flowers and his team, followed in 1944 and 1945 by nine Colossus Mark 2s. These were used at Bletchley Park in Cryptanalysis of the Lorenz cipher.