Saint Hill House, as it was originally known, was built in 1792 by Gibbs Crawfurd – Member of Parliament for the rotten borough of Queenborough – to a design attributed to Benjamin Henry Latrobe.

[2] Prior to the extensive modifications made in the late 19th and 20th centuries, the house comprised a three-storey central block and symmetrical two-storey flanking wings, all with hipped roofs behind parapets.

[2] Later owners included Edgar March Crookshank and Drexel Biddle, who commissioned the famous Monkey Mural which was painted by John Spencer-Churchill, nephew of Sir Winston Churchill.

[citation needed] During the Second World War it was used as a convalescent home for Royal Air Force officers undergoing reconstructive surgery at East Grinstead's Queen Victoria Hospital.

[8] L. Ron Hubbard, the founder of the Scientology organisation, bought the Saint Hill estate from the Maharaja of Jaipur, Man Singh II, in 1959 for a reported price of £18,000.

[14] Saint Hill Manor is now a museum that features the works of L. Ron Hubbard, and exhibits about what the Scientology organisation claims are his accomplishments.

[12] Following the completion of the renovations, the Church of Scientology purchased seven new 29-seater ADL Enviro200 midibuses to transport the 400 staff members between the manor and the town of Crowborough, 14 miles (23 km) away.

[16][17] Prior to the 2024 International Association of Scientologists event, which was to be held there on 25 October 2024, the Church of Scientology asked the Mid Sussex District Council to put in place a public spaces protection order to prohibit protesting outside the property.