With the fall of Constantinople to Crusaders from the West the Cistercian Order found a new area for development. Cistercians had taken an active part in the Fourth Crusade and they were ready to share in the process of settlement which followed hard on the conquest of the Empire and Greece. The fortunes of the Cistercians in the East waxed and waned with great rapidity, paralleling the course of the Latin Empire itself: between 1204 and 1276 the Order acquired at least twelve houses and lost at least nine of these. The interesting but unspectacular history of the Cistercian Order in the Latin Empire and Greece has received little attention, either from historians of the Order itself or from those scholars who have treated the history of the Latin conquest and occupation. The main purpose of this study is to investigate the foundation, development and final abandonment of the Cistercian houses in the Empire and Greece, to explore the activities of Cistercian abbots and priors in the affairs of the Empire, and to examine the contacts between Cistercians of East and West. But since the interest of the Cistercians in Constantinople and Greece began with their participation in the Fourth Crusade, consideration will first be given to their activity as Crusaders.