the heir presumptive to the kingdom. Boniface's cousin Philip of Swabia was married to Irene Angelina, a daughter of the deposed Byzantine emperor Isaac II Angelos and niece of Conrad's second wife Theodora. In the winter of 1201 Boniface spent Christmas with Phillip in Hagenau, and while there also met with Alexios IV Angelos, Isaac II's son, who had escaped from the custody of his uncle Alexios III Angelos. At this time the three discussed the possibility of using the crusading army to restore Alexios' right to the throne. Both Boniface and Alexios travelled separately to Rome to ask for Pope Innocent III's blessing for the endeavour. Boniface was specifically told by Innocent not to attack any Christians, including the Byzantines. The Crusader army was in debt to Enrico Dandolo, the doge of Venice, who had provided their fleet. He instructed them to attack the rebellious cities of Trieste, Muggia, and Zara and beat them into submission before sailing for Cairo. The Pope was angered by these Christian cities being attacked by a Crusader army. Dandolo, was now the true war leader of this Crusade, with Boniface as only a figurehead. Alexios IV Angelus made many promises to the Crusaders and their principal financier, the doge of Venice, for riches and honors if they would help him reclaim his empire. Dandolo placated the Pope by having Alexius Angelus promise to submit the Orthodox Church to Rome when he was restored to his throne in Constantinople. This being done, the fleet set sail for Constantinople in 1203. After the conquest of Constantinople in 1204, Boniface was assumed to be the new emperor, both by the western knights and the conquered Byzantine citizens. However, the Venetians vetoed him, believing that he already had too many connections in the Empire and, likely, felt that they would not have as much influence in the empire if Boniface was in control. Instead, they chose Baldwin of Flanders. Boniface founded the Kingdom of Thessalonica and also held all the territories that lay east of Bosphorus and territories in Crete, though he later conceded Crete to Baldwin. Late 13th and 14th century sources suggest that Boniface based his claim to Thessalonica on the statement that his younger brother Renier had been granted Thessalonica on his marriage to Maria Komnene in 1180. Boniface was killed in an ambush by the Bulgarians on 4 September 1207, and his head