Windsor Castle in England holds the official title of the longest-occupied castle in the world. It has been a primary residence for British monarchs for over 950 years, ever since it was founded by William the Conqueror in the 11th century. Since then, it has been the home of 40 successive monarchs, including Queen Elizabeth II, who spent much of her later years there. Unlike many historic castles that function purely as museums, Windsor remains a fully operational royal palace, hosting state banquets, official visits, and the King's residence on many weekends. The castle covers approximately 13 acres and combines elements of a fortification, a palace, and a small town. While parts of the castle are open to the public (such as the State Apartments and St George's Chapel), other areas remain strictly private for the Royal Family and their staff. This continuous occupation has resulted in a fascinating architectural mishmash, with styles ranging from original Norman walls to Gothic grand halls and 19th-century royal apartments.