As the Ribbungs were now out of the way and could no longer be made to serve his purposes, the earl hatched a new plot which, on account of its ingenuity, ran less risk of premature detection. He professed a desire to take the cross, and began warlike preparations on a grand scale. He obtained from the Pope permission to exact one twentieth of all the ecclesiastical revenues of the province of Nidaros in aid of his enterprise, and satisfied his conscience by endowing the Church, in return, with his great family estate, Rein, which was converted into a nunnery. Extreme caution was characteristic of Skule; and he meant, this time, to leave nothing to chance. He began at once to build ships, and to gather warriors about him from all parts of the country. As the Danish king, Valdemar the Victorious, had now regained his liberty, he could also count upon his aid, and a formal agreement was made between them in accordance with which Skule should assist the king in recovering his lost provinces. In return for this service Valdemar promised to put Skule on the throne of Norway. That some such agreement must have existed is obvious from the fact that the earl actually set sail for Denmark (1227), without asking Haakon's permission, but was met on his way by the latter and informed of the disastrous defeat of his ally at Bornhöved. He then concluded to await developments; as he would run too great a risk in visiting Denmark, while Valdemar's enemies had the upper hand. Putting on a bold face, he joined his fleet to that of his son-in-law and returned to Bergen. The king, although he did not deceive himself as to Skule's purposes, kept his counsel and feigned ignorance. Nay, he even carried his generosity so far as to lend the traitor ships and provisions when, the following year, (1228) he set out once more to visit the king of Denmark. Since his defeat at Bornhöved, Valdemar was indeed much less formidable than before his captivity, and the warlike spirit had wellnigh left him. Haakon may therefore have suspected that, surrounded as he was with enemies, both on the south and the west, he would scarcely care to add another on the north. Moreover, Haakon had by this time secured the friendship of the German emperor, Frederick II., who was a bitter enemy of Denmark, and he might, therefore, have a chance to keep Valdemar in check, in case he should lend a favorable ear to the earl's persuasions. Under these circumstances he hardly exposed himself to any risk, nay hoped, perhaps, by facilitating his father-in-law's approach to the Danish king, to convince him of the futility of all his plottings. If that was his intention, he must have been disappointed in the result. For when Skule returned he had added to his power for mischief, by obtaining the northern half of the Danish province of Halland in fief, thereby becoming the vassal of a foreign prince, who, moreover, was the enemy of his own king.