SIS (MI6) Technical Security Department
Hanslope Park was originally acquired by the Foreign Office at a time when Britain's Secret Service was in its infancy and GCHQ-type work was done at nearby Bletchley Park, in the days of Alan Turing.
Hanslope has been massively expanded in more recent decades. Under the title "Her Majesty's Government Communications Centre" (HMGCC), it now houses annexes full of the latest supercomputers.
The Hanslope Park estate (below) is also home to MI6 operatives who process and analyse data sent from Government Communications Headquarters in Cheltenham and Menwith Hill in North Yorkshire, especially data intercepted from the foreign embassies in London.