In 1393, Louis of Orleans had a fortified residence built near Compiègne. Pierrefonds was designed to keep an eye on trade between Flanders and Burgundy, which were the fiefdoms of the Dukes of Burgundy, who were rivals of the Orleans .Later on the citadel remained an appanage to the family.
In 1616, Louis XIII laid a fatal siege to Pierrefonds castle , taking it, then dismantling it .This great ruin was forgotten until it was bought by Napoleon I in 1810. Napoleon III turned Pierrefonds into an occasional residence , In 1857, he entrusted the restoration work to the architect Violet-le-Duc.
***From August 31st to September 18th 2009, the BBC team came back to Picardy to shoot the reminder of Merlin 's second season.The castle was chosen for its classic look. (less info)