After the mid-11th century, the Roman Church expanded, insisting on the supremacy of the pope in the entire Christian world, and by the time of Innocent III's reign, the papal power was at its peak. Innocent further expanded the influence of the Roman Church, not only trying to make the Church of Cyprus, Bulgaria and Armenia submit to the authority of the Pope, but also strongly hoping to bring the Byzantine Church under his rule, and he strongly urged Alexius IV, who became Byzantine emperor, the leaders of the crusaders, the military bishops, the Doge of Venice, etc., to force the Byzantine Church to obey the Pope.
Therefore, he did not really take steps to stop the turn of the Crusades. The Pope tried to exonerate himself and at the same time sought to expand the influence of the Roman Church. Therefore, when the leaders of the crusaders attributed the reasons for their turn to necessity and for the sake of the Roman Church (calling the Byzantines disobedient to Rome, unwilling to aid the Holy Land, etc.), the Pope refuted it, accusing them of using it as a cover to justify the turn of the Crusades, drawing a line with them, and exonerating themselves; At the same time, pressure was exerted on the leaders of the crusaders and the accompanying bishops to fulfill their commitment to the Roman Church, to unify the Church, to subordinate the Byzantine Church to the Pope, and to recover the Holy Land. The pope's expansionist ambitions were epitomized in his attitude after the fall of Constantinople in 1204. Before the fall of Constantinople in April 1204, the Pope repeatedly denounced the crusaders for ignoring his orders forbidden to attack Christians and trying to keep themselves out of the way; However, once the Latins captured Constantinople, the Pope was overjoyed and stopped mentioning the excommunication of the Crusaders, and immediately placed the Latin Empire (1204-1261) under his protection; The Crusaders had vowed to pay compensation to Hungary, but had not fulfilled their oath, and Innocent did not force them to do so.
He even announced that with the help of the newly returned Byzantine Church, the ancient Christian territories would finally be liberated from Islamic rule, all Christians would return to St. Peter's Church, many pagans would convert, and the entire Jewish nation would be saved. Thus, in March 1204, the Venetians signed a spoil-sharing agreement with the French Crusaders, which stipulated that the Crusaders would remain in Constantinople for another year, and the Pope did not question their delay in reaching the Holy Land; Not only that, but in a letter to Constantinople in 1205, he asked them to stay in Constantinople for another year; However, he became furious with the Venetians for dividing up church property, threatening to expel them if they continued to divide church property. To ensure the obedience of the Byzantines to the Roman Church, he sent papal envoys to the Latin Empire; wrote to all the Byzantine clergy asking them to obey the papal envoys or be punished; Even in July 1205, when the Pope learned of the three-day sack of Constantinople by the Latins, although he expressed anger and disgust, he was not willing to return Constantinople to the Byzantines, not only that, but he also hoped that the Latins would further expand their power in the original Byzantine territory.
Therefore, although the Pope did not participate in the conspiracy, anticipating that the development of things was in his own interest and desire, he constantly put on the appearance of a sanctimonious and decent gentleman to exonerate himself; At the same time, acquiescence in developments was given in order to ensure the expansion of the Roman Church's sphere of influence, waiting for the fruits of the war. It can be seen that Innocent III was insidious and cunning, he knew the conspiracy that prompted the turn of the Fourth Crusade, and in order to keep himself innocent, he tried to avoid getting involved, and publicly condemned the turn of the Crusades against the Christians and the Crusades, keeping himself out of it; At the same time he acquiesced to the turn, providing legitimacy to the turn in order to expand the sphere of influence of the Roman Church.
