This study deals with a phenomenon common during the time of the crusades in the Holy Land: Christian captivity by the Muslims. The crusades will be perceived not only as a matter of military concern or as a settlement movement, but also as a framework by which Latin Christendom interpreted its own history. Based on this system of reference the social, political, economic and cultural significance and implications of captivity for the crusading movement and the crusader principalities in Outremer will be analysed.