Guglielmo del Monferrato (1136 – 1191), often anglicized as William of Montferrat, was a Crusader in the army of King Richard I of England, Marquess of Montferrat and, secretly, a member of the Knights Templar. Following Acre's conquest, Montferrat became the regent of the city, and as a result of Al Mualim's plan to free the Kingdom of conflict, he became the fifth target of the Levantine Assassin Altaïr Ibn-La'Ahad.