 In summary, the castle was fortress of the Viscounts of Béarn, Castle of Fébus, birthplace of the good King Henry IV ("Nouste Enric") and royal residence in the Renaissance.A first defensive tower desired below the castle by Gaston Fébus, then called the "Tour du Moulin" [tower of the mill] for a time, was built along a water channel operating the mill of the castle as early as the 15th century.The "Tour de la Monnaie" [Money Tower] was named according to Henri d'Albret who, in 1554, used it as a mint.