466 THE HISTORY OF MEDIEVAL EUROPE Corfu, many other islands and coast cities of the Greek peninsula, and certain quarters of Constantinople. Boniface of Montferrat was given a kingdom about Thessalonica ; and numerous other petty fiefs, such as the Principality of Morea and the Duchy of Athens, were created for the crusaders in central and southern Greece. Their holders were nominally vassals of the Latin emperor. The Greek Patriarch of Constantinople was replaced by a Venetian, and Innocent, who had distrusted and forbidden the digres- sion of the crusade to Constantinople, was now reconciled to it by the prospect of seeing all southeastern Europe under papal control. But this did not alter the fact that the pope and his legate had failed to direct the course of the crusade. Moreover, all prospect of the crusaders continuing their route to Syria had vanished ; the crusade ended at Constan- tinople. During the next few years Innocent was occupied first with the Albigensian Crusade and then with preaching a Innocent crusade to aid the King of Castile against the and the Mohammedans in Spain. The pathetic Children's Crusade also occurred during his pontificate. The crusade to the East was again urged at the Fourth Lateran Council, but no armed expedition of consequence resulted. Innocent was always talking about the recovery of Jerusa- lem, but he himself was partly responsible for keeping the armies of Europe otherwise employed, as when he incited the barons to rebel against John and when he urged Philip Augustus to invade England, or when he allowed the King of Hungary to delay indefinitely his crusading vow because his presence was needed as a check upon Philip of Siiabia, or when he kept a French knight, Walter of Brienne, in southern Italy to aid him in conquering the Sicilian king- dom. But while Innocent had failed to recover Jerusalem, the crusades of his reign led to an extension of Latin Chris- tendom in both the Balkan and Spanish peninsulas. Innocent probably deserves to be called the greatest monarch of the Middle Ages. He wielded a wide interna- tional authority. But while he achieved notable triumphs,
