While focusing on the relationship between the papacy and the 14th-century crusades, this study also illuminates other fields of activity in Avignon, such as papal taxation and interaction with Byzantium. Using recent research, Housley covers all areas where crusading occurred--including the eastern Mediterranean, Spain, eastern Europe, and Italy--and analyzes the Curia's approach to related issues such as peacemaking between warring Christian powers, the work of Military Orders, and western attempts to maintain a trade embargo on Mamluk, Egypt. Placing the papal policies of Avignon firmly in context, the author demonstrates that the period witnessed the relentless erosion of papal control over the crusades.