International audienceThe fortification represented one of the main architectural tools at the time of the Crusades in the management and in the resolution of the conflicts opposing the Crusaders to the Muslims in the Bilād al-Šām. It allowed the surveillance of the borders on all sides and the development of a rural economy and of dense agglomerations in the fiefs or in the iqṭāʻ protected by castles or towers. During its main phase of development between the end of the 12th century and the end of the 13th century, the fortification became also for the Ayyubid and Mamluk sovereigns the privileged instrument for the establishment or the consolidation of their power in the Muslim territories that still escaped their control or in the provinc...