The Château de Boulogne-sur-Mer is a castle in the French seaport of Boulogne-sur-Mer, in the Pas-de-Calais département. It houses the Boulogne museum. The castle was built in the 13th century by Philippe Hurepel (1180-1234), count of Boulogne and son of Philip II of France. Following the death of his half-brother, king Louis VIII after a short three-year reign, Hurepel was one of the leaders of a rebellion against the regent, Blanche de Castille, mother of the minor Louis IX. He constructed castles at Calais and Hardelot and refortified Boulogne. The castle is built in the eastern corner of the medieval walls surrounding the Haute Ville (literally, high town - the part of Bologne on the hill). The walls themselves were reconstructed by Hurepel. The eastern part of the castle was built ove