Meanwhile the real warfare was in the east. The Mongols had swept through Poland and Hungary before turning south to ravage the Balkans. Their advance enabled the Muslims to regain control over Jerusalem, leading to calls for another crusade. Both Henry and Louis took up the cross, but only the king of France left. For Henry, Christian duty was more about ritual and forms. He preferred mass to sermons, taking oaths to actually abiding by them. Besides, there was trouble brewing in Gascony. With Louis gone, Henry saw his chance to consolidate control over the unruly local nobility without any interference from his brother-in-law. He asked his other brother-in-law, Simon de Montfort, to go there and restore order. Simon was also committed to the crusade and so drove a hard bargain before he would accept his offer. What he wanted most of all from Henry was no interference. The king agreed but, as with all his other oaths, this one also went by the wayside. Henry recoiled from the stern measures de Montfort used to put down the factional fighting, perhaps seeing too much of his father, the Scourge, in him. In the only letter of Simon’s to survive, he explained to Henry that his task was to uphold the rights of the king and the common people against these ruffians. Henry must have been dumbfounded when he read this. What were these rights of the common people and what did they have to do with him?