Also in 1201, Philip was visited by his cousin Boniface of Montferrat, the leader of the Fourth Crusade. Although Boniface's exact reasons for meeting with Philip are unknown, while at Philip's court he also met Alexius Angelus, Philip's brother-in-law. Some historians have suggested that it was here that Alexius convinced Boniface, and later the Venetians, to divert the Crusade to Constantinople and restore Isaac II to the throne, as he had recently been deposed by Alexius III, Alexius and Irene-Maria's uncle.