The Papacy and Crusading in Europe, 1198-1245

An ''internal'' crusade is defined as a holy war authorized by the pope and fought within Christian Europe against those perceived to be foes of Christendom, either to recover property or in defense of the Church or Christians.  This study is therefore not concerned with those crusades authorized against Muslim enemies in the East and Spain, nor with crusades authorized against pagans on the borde...