The Crusades were a series of military campaigns conducted in the name of Christendom and usually sanctioned by the Pope. They were military campaigns of a religious character typically characterized as being waged against pagans, heretics, Muslims or those under the ban of excommunication.[3] When originally conceived, the aim was to recapture Jerusalem and the Holy Land from the Muslims while supporting the Byzantine Empire against the "ghazwat" of the Seljuq [4] expansion into Anatolia. The fourth crusade however was diverted and resulted in the conquest of Constantinople. Later crusades were launched against various targets outside of the Levant for a mixture of religious, economic, and political reasons, such as the Albigensian Crusade, the Aragonese Crusade, and the Northern Crusades.