Gatehouse and attached south range

This structure forms the south side of the stable yard at Bletchley Park. It consists of a central gateway flanked by single-storey ranges to the east and west, each with a half-hipped roof. The western range forms the south return of the west stable range and was originally slightly detached.

The gatehouse and ranges were built around 1883–88 for Herbert Samuel Leon, following his purchase of the estate in 1883, to store apples, pears and plums produced on the property. Edward Swinfen Harris altered and extended the building around 1890. In 1938–39, Hubert Faulkner, a local builder, converted the structure to provide accommodation for the Government Code and Cypher School.

Plan and Construction

The building is a long range aligned east-west, enclosing the south side of the stable yard. It adjoins the south end of the west range, now known as The Bungalow and attached stables range.

Exterior

The building is one and a half storeys high. The gatehouse, which faces across the rear of Bletchley Park, is built of timber raised on brick pilasters on the flanking walls, with posts rising from stone pads. It has trefoil-pierced arched braces to a high horizontal lintel on each side, with a boarded soffit containing an access trap for a vertical iron stair.

The superstructure housing the clock mechanism is gabled on the north and south faces, framed with square panel decorative framing and pebbledashed infill. Two keyed bronze clocks face the yard and the rear of the house. Bargeboards carved with stepped arcading rise to meet at a dropped pendant. The roof is plain tile with crested ridge tiles. Two smaller gables of similar construction face east and west over the linked buildings. At the centre of the roof, standing on a tiled octagonal base below ridge level, is an octagonal louvred belltower with a lead-covered ogee cap carrying a wind vane with a wyvern crest.

Running east from the gatehouse is a single-storey range of eight bays with three single-bay two-storey gables facing south. These have deep bargeboarded eaves and a plain Dreadnaught nib-tiled roof, probably from a re-roofing, half-hipped at the gatehouse end with crested ridges. The first and third gables from the gatehouse originally had wide brick-arched openings and double doors for access to the fruit stores; these are now infilled. Two original two-light timber casement windows survive in the gables, along with a single door and various replaced paned timber windows on the ground floor. The eighth bay was apparently added in the late 1880s or early 1890s by Edward Swinfen Harris and has a door and windows in the gable end.

The yard elevation, facing north, has a high chamfered plinth, later rendered and colourwashed, with various replaced windows. The added end bay is returned by half a bay under a hipped roof carried on four chamfered posts, covering an entrance and window from the yard at the east end. There are two small side windows with coloured leaded glass. Beyond the end gable, a short crenellated wall running east from the south face of the building has a two-centred gateway arch with a framed and panelled door with decorative ironwork on the south face.

West of the gatehouse is a two-bay single-storey returned end of the west range of the former garage. The front is now infilled with wire-cut Fletton bricks from when the building was converted to a dwelling for the site surveyor. It has a similar tiled roof half-hipped against the gatehouse and appears to have been built independently of the gatehouse and linked later.

Interior

The range east of the gatehouse is subdivided by plastered brick partitions, with a stud wall forming a corridor on the south side. The floors are boarded. There are two chimney stacks with stepped tile and brick fireplaces. The single-purlin roof rests on king-post trusses and intermediate studs above and below the collar.

Historical Context

During the Second World War, the section east of the gatehouse, then known as "the bungalow", was re-partitioned to accommodate the Enigma Attack section of the Government Code and Cypher School.

The group of buildings intimately associated with and lying to the north of Bletchley Park consists of two ranges forming the south and west sides of the former stable yard, a row of three cottages now forming the north side of the yard, and two estate buildings—now private dwellings known as The Bungalow and Fenella—continuing the west range further north beyond the north gate. The range of eight loose boxes enclosing the stable yard on the east was demolished in 1937.

Bletchley Park succeeded Water Hall, a mansion built in 1711 by the eminent historian Dr Browne Willis, co-founder of the Society of Antiquaries of London, on land purchased by his ancestor from the second Duke of Buckingham in 1694. The house was demolished in 1798 by Thomas Harrison, steward to Earl Spencer, the then owner. The estate was divided and bought in 1865 by a descendant, Spencer Harrison, who sold it in the 1870s to a Mr Coleman, who erected a new house that now forms the rear part of Bletchley Park. This was enlarged in 1881 by a succeeding owner, Samuel Beckham, who had bought it with 430 acres.

The estate was sold again in 1883 to Herbert Samuel Leon, an eminent stockbroker, financier, company director, and later a county councillor and Liberal MP for North Division of Buckinghamshire (1891–1895). He was also a newspaper proprietor, successful farmer, and good friend of Prime Minister David Lloyd George, who frequently stayed at the house. Leon was created baronet in 1911, and through his local interest and beneficence, the town benefited considerably. Sir Herbert considerably enlarged the house immediately following his purchase, adding an opulent new south front range, though the identity of his architect is not known. He also developed ancillary accommodation to the north around a stable yard and his extensive nursery gardens, which included a walled garden and orchid houses.

Further buildings on the estate, which at one time employed about 200 staff, included the Lodge (1886), Dauphin House for the mechanical and electrical engineer (1886), the Laundry (1888), Lodge and Pavilion on Buckingham Road (1896–97), a house in School Lane (1899), and the eight Noel Cottages on Church Green Road (1904). Sir Herbert died in 1926, and Lady Fanny Leon continued to live there and actively support the community until her death in 1938. The estate was then further divided and sold.

After March 1938, with tensions in Europe rising fast following the Austrian Anschluss, the then-vacant property was identified from a list of available properties by Commander Alastair Denniston of the Ministry of Works as a new dispersal location for the Foreign Office's Code and Cypher School, later renamed GCHQ. The first elements of the organisation, known flippantly as "Captain Ridley's Shooting Party", moved in during August 1939. The accommodation in the house soon proved insufficient for the rapidly growing organisation, and personnel spilled over into all outbuildings and a range of hastily erected prefabricated huts.

The organisation, under Rear-Admiral Sinclair, who was later referred to simply as "C", was equipped with and developed the Enigma electro-mechanical deciphering machines originally designed in the 1920s. The enemy coded messages deciphered here by the 7,000-plus staff were greatly instrumental in the prosecution and successful outcome of the Second World War. The accommodation was soon expanded into a series of huts, with further expansion occurring in response to German expansion into the Balkans and North Africa. The station was responsible for developing methods to penetrate up to 58 German Enigma codes and to sift the intelligence, termed top secret ULTRA, for direct transmission to the Prime Minister, Whitehall, and to operational field stations known as the Special Liaison Units.

One of its most significant early successes was the interception of the German Knickebein beam guidance system in June 1940. Later, it became the hub of the Battle of the Atlantic and was able to forewarn accurately the disposition of German defences prior to Operation Overlord. It also identified secret work at Peenemünde and forewarned the V-weapon attacks.