A triplex penthouse within a converted mansion house on a historic English estate famed for its tenure as Royal Air Force (RAF) headquarters, hit the market in July with an asking price of £2.4 million (US$3 million).

Known as Bentley Priory, the 57-acre estate in Stanmore, Middlesex, once served as a royal residence of Dowager Queen Adelaide, consort of King William IV. But almost a century later, it was the headquarters for the RAF’s Fighter Command.

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Fighter Command served throughout World War II and earned fame during the Battle of Britain in 1940, when it defended the U.K. against attacks by Nazi Germany’s air force, the Luftwaffe.

The estate remained nearly unscathed during the war. Two bombs, thought to be overspill from London raids, were dropped on the site destroying a wooden building, though no casualties were recorded.

The RAF were Bentley Priory’s longest serving residents, occupying both the mansion and grounds until 2008.

In 2011, the estate and its buildings was purchased by developers and turned into luxury housing.

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The triplex penthouse is dubbed the Dowding Suite after Sir Hugh Dowding, the commander of RAF Fighter Command during WWII. It’s found within the estate’s mansion house and has three bedrooms, double-height ceilings, sash windows and a glass-panelled staircase. There are more residential units scattered across the estate.

The penthouse’s three terraces have views across the estate’s formal gardens and grounds and into central London, according to the listing with Savills Norwood, the estate agency handling the sale. They could not be reached for comment.

Mansion Global could not identify the owners of the penthouse.

The residents share the estate with the Bentley Priory Museum, opened in 2013 by Prince Charles, and commemorating the estate’s role in the Battle of Britain.