I notice here one fact characteristic of both the King and his century. Many of these amicable transactions with his great vassals were almost immediately followed by the departure of the latter on a new crusade. The Christian world had not renounced the hope of freeing Jerusalem and the Holy Sepulchre from the yoke of the Mussulman. The desire to astonish the world by startling acts of penance, and the love of military adventure, still agitated both the highest and lowest ranks of feudal society. Pope Gregory IX. continued to preach a crusade--a double crusade--to Jerusalem for the deliverance of the Holy Sepulchre, to Constantinople for the succour of the recently established Latin Empire, which was already tottering. The King of France found, doubtless, that it was very convenient to extend his dominion thus without war at the expense of his vassals, and to get rid of these turbulent individuals. But to these reasons of general or private interest was certainly added the personal influence of Louis, already passionately absorbed in the thought of the glory and religious salvation which he hoped to win for himself in one of these expeditions. As early as 1239, some of the principal vassals with whom he had just concluded advantageous treaties--the Counts of Champagne, Bretagne, and Mâcon--started for Palestine at the head of an army of Crusaders, numbering (so it is said) fifteen hundred knights and forty thousand squires. Louis was not content simply with encouraging and promoting this enterprise. 'He desired,' says De Tillemont, 'that Amaury de Montfort, his constable, should in this war serve Jesus Christ in his stead. Therefore he gave him his arms and granted him a daily sum of money, for which Amaury thanked him on his knees. That is, he did him homage after the custom of the time. The Crusaders were much rejoiced to have this noble lord with them.' {25} The heavy sickness from which the King suffered five years after, and his pious thankfulness for his cure, are said to have given rise to his resolve to take the Cross. But this is a grave mistake, for from the year 1239, when he saw his chief vassals departing for Palestine with the cross embroidered on their shoulder, the heart of St. Louis had already taken flight towards Jerusalem. {26} Chapter IV. Relations Of St. Louis With His Vassals. His Feudal Conflicts. War With Henry III. Of England.