Bentley Priory, near Stanmore in the London Borough of Harrow, was built in 1766 and extended in 1788. It was the final home of the Dowager Queen Adelaide, Queen Consort of William IV, before her death there in 1849. Afterwards the building was used as a hotel and girls' school before being acquired by the RAF in 1926.
RAF Bentley Priory became a non-flying Royal Air Force station. It was the headquarters of Fighter Command during the Battle of Britain and throughout the Second World War. The (later Royal) Observer Corps were also based at the station from 1936. In 1940 an underground bunker was opened which oversaw Fighter Command activity across the country. During the war, there was damage caused by conventional bombs and by both V1 and V2 ‘vengeance’ weapons.
Post-war, the bunker was modified to offer protection from nuclear weapons and little of the original WW II construction remained visible. The Royal Air Force station closed in May 2008, with all units relocating to new accommodation at RAF Northolt, a few miles away. English Heritage declined to list the bunker - despite its pivotal role in history it was felt that there were similar examples already preserved elsewhere.
The mansion house and grounds are now an exclusive housing estate. Part of the development secured the Officers' Mess which now forms the Bentley Priory Museum; this focuses on the Battle of Britain period in particular. The bunker has been infilled but the entrance preserved as a small reminder of what once lay beneath.