The Fifth Crusade (1217-1221 CE) was called by Pope Innocent III (r. 1198-1216 CE) with the objective, like previous crusades, of recapturing Jerusalem from Muslim control; only this time the strategy was to weaken the enemy by first attacking Muslim-held cities in North Africa and Egypt, then controlled by the Ayyubid dynasty (1174-1250 CE). The idea that Egypt would be an easier target than Jerusalem proved to be mistaken, and the campaign was not successful. The Crusader army, although eventually conquering Damietta, was beset by leadership squabbles and a lack of sufficient men, equipment, and suitable ships to deal with the local geography. Defeated on the banks of the Nile, the Crusaders returned home, once again, with very little to show for their efforts.
This is a companion discussion topic for the original content at https://www.worldhistory.org/Fifth_Crusade/.