It appeared that Skule had levied troops and contributions, outside of his own fief, accordingly in the king's domain, and Haakon was so incensed at this fresh infringement of his rights that he wrote him a letter, in which he threatened him with war, in case he persevered in disregarding their agreement. The earl replied to this letter by immediately setting sail for Denmark. He had evidently taken a great resolution. What this resolution was is easy to guess. [Illustration: OLD NORSE CAPITALS.] The kings of Denmark had, since the days of Harold Bluetooth, claimed overlordship over Viken, and they had repeatedly fomented rebellion in Norway for the purpose of regaining the lost province. Skule's intention was now to thrust Haakon from the throne by the aid of Valdemar the Victorious, and to take the entire country in fief from him. But to his unutterable astonishment, when he arrived in Denmark, Valdemar was nowhere to be found. He had been captured, five days before, by Count Henrik of Schwerin, and was now languishing with his son in a prison in Mecklenburg. Bitterly disappointed, Skule returned home, and was compelled to resume his mask of benevolent interest in his son-in-law's affairs. The latter had just filled his eighteenth year, which, in the case of princes, was regarded as the age of majority. He needed, therefore, no longer a guardian, and custom seemed to demand some ceremony on his formal assumption of the government. An assembly of notables was therefore summoned to meet in Bergen (1223), where Archbishop Guttorm, who, in the meanwhile, by concessions, had been bribed to take the king's side, solemnly reaffirmed his right to the throne. Sigurd Ribbung's claim was pronounced invalid, as was also that of Squire Knut, the son of Haakon Galen and Christina, who had sent representatives to the meeting. Earl Skule saw from the beginning that the sentiment of the assembly was so overwhelmingly in Haakon's favor, that it would be of no use for him to urge his pretensions. He therefore contented himself with extorting as favorable terms for himself as possible at the renewal of his compact with the king. After many negotiations he exchanged his southern fief for the northern third of the country, extending from the North Cape to the southern boundary at Söndmöre. But he still remained, in name at least, a royal vassal, and was compelled to swear allegiance to the king; although he enjoyed all the royal revenues from his fiefs, and paid no tax or tribute to any one.