Despite the railway, the hotel was never a financial success, so the Gordons and their eleven children moved from 'Glenthorn' into the Priory and lived there until the death of Frederick Gordon in 1908. The Priory changed hands yet again and was re-opened as a girls school. The school housed 70 boarders, and as part of its music focus, maintained a number of pianos in separate soundproof rooms. For several years the school prospered as a female preserve. Male staff were required to leave by 9:30pm when the gates were locked. Any man inadvertently entering the grounds was politely but rapidly removed. Local actor and journalist Pete Knobbler referred to his great-uncle's attempt to remain in the school after hours in an article published in the Harrow Observer in 1983. After World War I, the school ran into financial trouble. At the end of the winter term, 28 December 1924, the school gates closed for good. In 1926 the Priory and part of the grounds was sold to the Ministry of Defence and it served as the Inland Area (Training Command). In the Second World War, Bentley Priory was the headquarters of RAF Fighter Command for which it gained historic significance. After the war the site took on various RAF administrative roles until final closure took place on 30 May 2008. The commander of RAF Fighter Command at the time of the Battle of Britain, Sir Hugh Dowding, was honoured with a peerage, as Baron Dowding of Bentley Priory in 1943. The estate and house was purchased in 2011 by developers City and County in conjunction with Barret Homes who planned to develop it into luxury housing. In 2013 an appeal was launched to turn the priory house into a museum commemorating its role in the Battle of Britain. The Bentley Priory Museum was formally opened to the public in September 2013 by Prince Charles. It commenced full public access in January 2014, managed by The Bentley Priory Battle of Britain Trust. The grounds are now Bentley Priory Nature Reserve, a Site of Special Scientific Interest.