 The Château de Pierrefonds includes most of the characteristics of defensive military architecture from the Middle Ages, though it underwent a major restoration in the 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.