So the old struggle between Guelf and Hohenstaufen was renewed. Both of the kings bid for the support of Innocent III, who openly proclaimed that the decision of the matter lay with him. Otto was willing to make the most reckless concessions to him; and as the pope naturally feared a revival of the power of the Hohenstaufen house should Philip be recognized, he decided in favor of the Guelf claimant in 1201. The grateful Otto wrote to him, "My kingship would have dissolved in dust and ashes had not your hand, or rather the authority of the Apostolic Chair, weighed the scale in my favor." Innocent appears here, as upon other occasions, as the arbiter of Europe. In the dreary civil wars which followed in Germany, Otto gradually lost all his friends. His rival's promising career was, however, speedily cut short, for he was murdered by a private enemy in 1208. Thereupon the pope threatened to excommunicate any German bishop or prince who failed to support Otto. The following year Otto went to Rome to be crowned, but he promptly made an enemy of the pope by playing the emperor in Italy; he even invaded the Sicilian kingdom of the pope's ward, Frederick, the son of Henry VI. [Sidenote: Innocent III the arbiter of western Europe.] Innocent then repudiated Otto, in whom he claimed to have "been deceived as God himself was once deceived in Saul." He determined that the young Frederick should be made emperor, but he took great precautions to prevent him from becoming a dangerous enemy of the pope, as his father and grandfather had been. When Frederick was elected king in 1212 he made all the promises that Innocent asked. [Sidenote: John of England becomes a vassal of the pope.]