Raymond de Bonnefons (1545-1607), a military engineer of King Henry IV of France, is at the origin of the plans for the keep of the citadel of Saint-Tropez. It takes the form of a hexagonal tower built around a vast interior courtyard. Accessible by a drawbridge, it is defended by an artillery platform and three circular turrets. The large bastioned wall and the system of moats and counterscarps surrounding the tower-keep were built a few years later. The fortifications of Saint-Tropez proved their effectiveness in resisting the attack of twenty-one Spanish galleys during the Thirty Years' War, which tore Europe apart from 1618 to 1648.