Windsor Castle is a royal residence notable for its long association with the English and later the British royal family, and also for its architecture. The original castle was built in the 11th century after the Norman invasion by William the Conqueror. Since the time of Henry I, it has been used by succeeding monarchs and is the longest-occupied palace in Europe. More than five hundred people live and work in Windsor Castle.
Originally designed to protect Norman dominance around the outskirts of London, and to oversee a strategically important part of the River Thames, Windsor Castle was built as a motte and bailey, with three wards surrounding a central mound. Gradually replaced with stone fortifications, the castle withstood a prolonged siege during the First Barons’ War at the start of the 13th century. A round keep now stands on the motte. Henry III built a luxurious royal palace within the castle during the middle of the century, and Edward III went further, rebuilding the palace to produce an even grander set of buildings. Edward’s core design lasted through the Tudor period, during which Henry VIII and Elizabeth I made increasing use of the castle as a royal court and centre for diplomatic entertainment.