Innocent III

Pope Innocent III (1160/1161 – 16 July 1216), born Lotario dei Conti di Segni, was Pope from 1198 until his death.

During his papacy, Innocent called for the Fourth Crusade, sending forth a marauding Christian army towards the Holy Land. This resulted in a sequence of events which culminated in the Crusaders.

Reference

 * Assassin's Creed: Revelations