Frederick was welcomed in Swabia, and the renown of the Hohenstaufen name and a liberal distribution of promises made his progress easy. Having arranged a treaty against Otto with Louis, son of Philip Augustus, king of France, whom he met at Vaucouleurs, he was chosen German king a second time at Frankfort on the 5th of December 1212, and crowned four days later at Mainz. Anxious to retain the support of the pope, Frederick promulgated a bull at Eger on the 12th of July 1213, by which he renounced all lands claimed by the pope since the death of the emperor Henry VI. in 1197, gave up the right of spoils and all interference in episcopal elections, and acknowledged the right of appeal to Rome. He again affirmed the papal supremacy over Sicily, and promised to root out heresy in Germany. The victory of his French allies at Bouvines on the 27th of July 1214 greatly strengthened his position, and a large part of the Rhineland having fallen into his power, he was crowned German king at Aix-la-Chapelle on the 25th of July 1215. His cause continued to prosper, fresh supporters gathered round his standard, and in May 1218 the death of Otto freed him from his rival and left him undisputed ruler of Germany. A further attempt to allay the pope's apprehension lest Sicily should be united with the Empire had been made early in 1216, when Frederick, in a letter to Innocent, promised after his own coronation as emperor to recognize his son Henry as king of Sicily, and to place him under the suzerainty of Rome. Henry nevertheless was brought to Germany and chosen German king at Frankfort in April 1220, though Frederick assured the new pope, Honorius III., that this step had been taken without his consent. The truth, however, seems to be that he had taken great trouble to secure this election, and for the purpose had won the support of the spiritual princes by extensive concessions. In August 1220 Frederick set out for Italy, and was crowned emperor at Rome on the 22nd of November 1220; after which he repeated the undertaking he had entered into at Aix-la-Chapelle in 1215 to go on crusade, and made lavish promises to the Church. The clergy were freed from taxation and from lay jurisdiction, the ban of the Empire was to follow the ban of the Church, and heretics were to be severely punished.