From the prison to which he had been consigned by Canute VI. the bishop of Sleswic was no inattentive spectator of events. He longed for revenge; but he must first recover his liberty. In this view he applied to the pope, to the archbishop of Lund, to many prelates of Denmark, and even to the queen, and interested them so far in his behalf, that Valdemar, at their intercession, agreed to release him, on the condition of his never again entering Denmark, or any other place where he might give umbrage to the state. Of these conditions the pope was a guarantee, and he repaired to Bologna; but that city he soon left to urge his interests with the chapter of Bremen, some members of which showed a disposition to elect him. The king immediately complained to Innocent III. that Bremen was, of all cities, that where the bishop, if elected, would be most likely to injure him; and the pope, admitting the justice of the plea, commanded the prelate to desist from aspiring to the vacant dignity. That command he disregarded. Philip of Swabia, now head of the empire, was hostile to the Danish king: from him the bishop readily obtained troops, and with them hastened to Bremen, where he was soon elected. But Burkard, the other candidate, being favoured by the chapter of Hamburg, which had a voice in the election equal to that of Bremen, also assumed the archiepiscopal dignity, and obtained troops from the Danish king. What confirmed the triumph of the latter was the suspension of bishop Valdemar by the pope, and the death of his patron Philip. Otho, the new emperor, concurred with the pope and with Valdemar in expelling the bishop from Bremen. But on the death of Burkard, bishop Valdemar was introduced to the see, with the full concurrence of the emperor. In revenge, the Danish king espoused the interests of Frederic II. king of Naples, in opposition to those of Otho. For this service the grateful Frederic ceded to the Danish crown the conquests which Valdemar and his predecessor, Canute VI., had made in the empire and in Slavonia. But the letters-patent containing this cession (dated from Metz in 1214) could have no validity, since Otho was yet obeyed by a considerable portion of the empire. Still the cession was a triumph. Not less so was the excommunication of Otho and of archbishop Valdemar by the pope. The first soon died; the latter, succeeded by the bishop of Osnaburg, retired to a monastery, and was for ever dead to the world.