The Château de Pierrefonds includes most of the characteristics of defensive military architecture from the Middle Ages, though it underwent a major restoration (19th century).In the 12th century, a castle was built on this site.Two centuries later, in 1392, King Charles VI turned the County of Valois (of which Pierrefonds was part) into a Duchy and gave it to his brother Louis, Duke of Orléans.From 1393 to his death in 1407, the latter had the castle rebuilt by the court architect, Jean le Noir