by Philip's murder, which occurred at Bamberg in June 1208. A feature of this struggle was the reckless way in which the rival kings gave away the property of the crown in order to gain adherents, thus enriching the princes and weakening the central government. Otto IV. becomes sole king. Otto was now again chosen German king, and to aid and mark the general reconciliation he was betrothed to the murdered king's daughter Beatrix. Nearly all the princes acknowledged him, and as pope and king were at peace, Germany enjoyed a period of comparative quiet. This however, did not last long. Having secured his coronation at Rome in October 1209, Otto repudiated the many pledges he had made to Innocent and began to act in defiance of the papal wishes. To punish him the pope put forward his own ward, Henry VI.'s son Frederick, who was living in Sicily, as a rival king. While Otto was warring in Italy a number of influential princes met at Nuremberg, at the instigation of Innocent and of his ally Philip Augustus of France, and invited Frederick to come to Germany. Otto then left Italy hurriedly, but he was quickly followed by his young rival, who in the warfare which had already broken out proved himself a formidable opponent. Seeking to mend his failing fortunes, the Welf went to France to support his ally, the English king John, against Philip Augustus, and at the battle of Bouvines (July 27, 1214) memorable in the history alike of Germany, of England and of France, his fate was sealed, although until his death in May 1218 he maintained a desultory warfare against Frederick. Frederick II.