In 1175, pope alexander iii used the promise of the same indulgence granted to crusaders in the holy land to encourage the christian rulers of león, castile, and aragón to go on the offensive against.. The acquisition of damietta and.
In the fifth crusade, put in motion by pope innocent iii before he died in 1216, the crusaders attacked egypt from both land and sea but were forced to surrender to muslim defenders.. There were as many different reasons for crusading as there were crusaders, but the single most common reason was piety.