A belvedere (a small pavilion or tower on top of a building) was first built on Shrubbs Hill, Windsor Great Park, in 1750. It was intended as a viewpoint from which to observe the picturesque landscaped gardens and lake. During the reign of George IV, it was enlarged and converted into a mock fort. Canons were set up around the battlements, and these fired salutes on important royal occasions, often answered by the guns of a model frigate on the Virginia Water lake.
Edward Prince of Wales, later King Edward VIII made the Fort his permanent home in the 1930s. He made significant changes to the interior, bringing it up to the highest standards of decoration and comfort. He also put a swimming pool into the grounds and took an active role in the remodeling of the gardens. Fort Belvedere became famous in the 1930s, as the place where King Edward VIII signed the Deed of Abdication and broadcast his abdication speech.
During the Second World War the Fort was taken over by the Commissioners of Crown Lands. Following the war, it had fallen into such a bad state of disrepair that demolition was considered. However, the Hon. Gerald Lascelles, first cousin of HM The Queen took on the house and restored it to its previous grandeur. It remains a private residence.
Davis, Ron and Dorothy, The Virginia Water Picture Book
Museum Press cuttings file