In the course of the thirteenth century, the crusade movement underwent significant changes. Its focus expanded beyond military expeditions against the Muslims as it came increasingly to be employed for political purposes and in defense of the faith. Increasingly, leadership of major crusading expeditions was under the control of secular rulers. Frederick II and Louis IX, though often contrasted, shared a common view of their role as leaders of the crusade. The role of the papacy, which through the early part of the century was central, became more marginal. While the religious ties of the crusade remained and may have moved even more to the fore, papal leadership became increasingly symbolic. By the late thirteenth and early fourteenth century, continuing adversity undermined efforts to maintain papal leadership.