'During the expansion of the RAF during the late 1930s, the command structure of the air defences of Britain was reviewed. New developments in radar technology and the capabilities of the new Spitfire and Hurricane fighter aircraft, together with the changing nature of the threat posed by the modern bomber aircraft used by the Luftwaffe meant that a comprehensive reorganisation was required. In a command network known as the Dowding System, Fighter Command was divided into four operational Groups, under the control of a central Headquarters at Bentley Priory. Each Group had its own geographical area of responsibility: 10 Group, South West England and South Wales; 11 Group, South East England; 12 Group, the Midlands; and 13 Group, north of the Humber and all of Scotland.

The location of the 13 Group HQ was chosen before the 27th September 1938. Initially there was a temporary above ground operations room brought into use by 24th July 1939 to coincide with the formation of the Group. At this time a permanent underground operations room was under construction, this was completed and was being fitted out by 3rd December 1939 becoming fully operational at 23.59 hours on the night of the 13th of March 1940.

The area controlled by 13 Group was relatively calm during the Battle of Britain, with the brunt of the German assault being borne by 11 and 12 Groups. After the end of the daylight phase of the Battle of Britain, the operational requirements of the air defence system were changed. On the 1st August 1940 Dyce and Wick sectors were transferred from 13 to 14 Group, a new formation covering the air defence of Scotland with a fifth protected Group Headquarters provided at Inverness. On 9th August 1940 13 Group was further reduced in size with the formation of 9 Group at Barton Hall, Preston (later RAF Longley Lane). the defences of Manchester, Liverpool, Birmingham and the Western Approaches.

This was to concentrate the defences of Manchester, Liverpool, Birmingham and the Western Approaches.

In another development following the Battle of Britain, it was recognised that the central command structure was in danger of being overloaded with information from the various radar stations and observation. To overcome this potential problem, each Group Headquarters were provided with a Filter Room to receive all reports of aircraft locations, to assimilate and assess this information in order to provide the most accurate possible picture to the Operations Room.

The Filter Room for Kenton Bar was built on a separate site, in Blakelaw Quarry. This facility was somewhat smaller than the Group Headquarters, but built to a similar pattern. Each Group was also provided with third smaller communications bunker; the location of the Communications bunker for Kenton is not known.

Throughout late 1940 and 1941, the nature of the threat changed again; the Luftwaffe stepped up its night operations against large cities and industrial targets. Through 1941, the majority of German operations seem to be attacks en route to and from Glasgow and Edinburgh and in many ways, the north-East appears to have escaped the worst of the night bombing.

The Operations Record Books from this period are a useful reminder that the role of the headquarters went beyond directing air defence operations. Documents bound in with the operational diaries include combat reports and the development of new tactics, particularly during the switch to night-bombing in late 1940 to 1941.

By 1943, the air defence requirements had changed again, with the increase in offensive actions against occupied Europe and the reduction of massed bombing raids on Britain. 13 Group was amalgamated with 14 Group on the 15th July 1943 and the Group Control was renamed RAF Blakelaw becoming a Sector Operations Room for Catterick and Ouston Sectors in 12 Group.

This change in role meant that the Filter Room apparently became redundant and was taken over by the Military Police in June 1944. The exact role of the Blakelaw bunker at this time is in some doubt; there were proposals to establish a joint USAAF/RAF command centre or even to convert the site into a Maintenance Unit but neither of these appear to have come to anything. In September of that year, the Filter Room was turned over to 321 Squadron, attached to 22 Group.

VJ Day (12th August 1945) marked the end of RAF Blakelaw as an active station. The Royal Observer Corps were stood down, and round the clock manning of the Operations Room was left to a skeleton crew.

The Kenton Bar site was placed on the surplus list in 1947 and the land surrounding the operations room was used for offices by the Ministry of Agriculture with a number of single storey brick buildings being constructed for the purpose. Many of the above ground buildings associated with the Group Headquarters were demolished at this time.

The sites of the two bunkers were subject to intense attention from competing interests. The emergence of the military threat posed by the Soviet Union and its Eastern European satellite states in the late 1940s led to the realisation that the civil defence infrastructure which had been so quickly run down after the end of the war was necessary again. The Civil Defence Act of 1948 and later regulations made under that act, required local governments to make provision for an infrastructure capable of carrying out the functions of the wartime ARP units; at the time, any future war with the Soviet Union was expected to be very similar to the previous war with Germany, though the additional damage caused by atomic bombing was seen as a major new threat.

In 1950 the Kenton Operations Room was proposed as a Sector Operations Centre for the Northern Sector in the Rotor scheme but discarded in favour of purpose built one near York (This was later built at Shipton but at this time only the area of York had been decided). At the same time the former Group Headquarters bunker at Langley Lane Preston (RAF Longley Lane) was refurbished as a Rotor Sector Operations Centre. The Kenton Bar bunker was selected for reuse as the Regional War Room for Region 1

Kenton Bar was unique amongst Regional War Rooms of this period in that it occupied an earlier structure, rather than a purpose-built facility: it seems likely that the existence of two suitable structures with existing secure communications links was too good an opportunity to miss.

In plan, the purpose-built regional war rooms were very similar to the fighter command Operations Room bunker, being focused on a central two level map room with observation galleries. The life-span of the original Regional War Rooms appears to have been quite short, though details are sketchy.

By the time that most of the purpose-built structures were nearing completion in 1955-6, the advent of nuclear weapons had led to an enormous change in the perception of the threat posed by the Soviet Union, and the needs of Civil Defence.

The threat now was of complete breakdown of central government with the Regional War Rooms being were superseded by Regional Seats of Government, fully autonomous regional command centres, hardened against nuclear attack. Some of the purpose built Regional War Rooms were adapted as Regional Seats of Government, but this was not the case with Kenton Bar which did not have the room for expansion required for the increased number of staff.

The exact date of closure of the regional war room is uncertain although it is thought that most of these facilities had been supplanted by Regional Seats of Government by around 1960.

After its use as war room ceased it was used as a training centre for RSG and later Sub Regional Control staff in Region 1. The presence of materials related to Exercise ARCADE confirms the continued use of the bunker.

It was deemed too near the City centre target area for use as War HQ for the Newcastle Sub Region remaining dormant with occasional staff training until about 1965, after that date it was used for storage for the government offices on site. In 1968 it was considered for use as a temporary Sub Regional Control until a purpose built one could be built in Hexham however nothing came of this.

In 1974 it was designated by the Home Office as War HQ for the new Tyne and Wear County Council. However it was never fitted out as the county which was a left wing stronghold refused to pay rent to the Home Office. They used the sub basement of Sunderland Civic Centre instead. Its final use was for storage for MAFF and other users of the government offices.

In recent years the government offices have been occupied by the Department for the Environment, Food and Rural Affairs (DEFRA), the Driving Standards Authority and the Inland Revenue. Recently the offices were vacated by these government agencies and all the 1950’s office buildings and some later ‘temporary’ buildings, were demolished. At the same time a former Royal Observer Corps underground post in the north west corner of the site was also demolished. The site is being developed for residential use.

The plan is to retain the bunker in a compound, which will form a park for residents of new development; the two bunker entrances will be in secure compounds. There are no funds available to restore bunker, but limited visits will be arranged from time to time. The original plan was for a northern branch of the Imperial War Museum, but the council zoned the area as residential and there was no provision for parking etc which stopped the plan being implemented. It has been suggested that a trust might be formed to finance restoration, but so far nothing has happened.'

- Nick Catford, Subterranea Britannica, 01/12/04, https://www.subbrit.org.uk/sites/kenton-bar-13-group-fighter-command-headquaters-and-regional-war-room/

There are various fascinating websites including the one above from where the extract is sourced. Newcastle City Council have published their own site on the area, found here: http://www.secretbunkernorth.org/

The Ordnance Survey Map, further above the page, was published in 1967 and shows the area as 'Government Buildings'. The purpose of the site was still likely kept secret due to the Cold War tensions of the time, but the complex was pretty large with a decent amount subterranean. Kenton wasn't too dissimilar back then, with much of the housing built remaining today, though many more developments have been constructed as well as modern structures taking the place of its predecessor, such as at Kenton School and Kenton Hall.