Olaf was succeeded both in Denmark and Norway by his mother, Margaret, who became reigning queen. The real heir to the Norwegian throne was, in accordance with the law of succession, the Lord High Steward (Drost) Haakon Jonsson, a grandson of Agnes, an illegitimate daughter of Haakon Longlegs. But he did not possess the power to assert his claim against Margaret, who, by skilful intriguing, had induced the archbishop, Vinald, and the majority of the clergy to take her side. The Norwegian Council of Regency, in which the partisans of the queen likewise preponderated, seemed ready to do any thing which she demanded, and even yielded to her wish in pledging themselves to choose her grand-nephew, Erik of Pomerania, as her successor (1388). In accordance with this promise they declared Erik, during the following year (1389), king of Norway, under the guardianship of Margaret, until he should reach his majority. The ambitious queen now turned her attention to Sweden, where she had a bitter and determined foe in Albrecht of Mecklenburg. He was remotely related to the royal house of Norway, and therefore believed himself to be the nearest heir to the throne. He was boiling over with animosity toward Margaret, whom he called "Queen Breechless," and never referred to, except with opprobrious epithets. As this kind of harmless ammunition produced no effect, however, he boldly assumed the title of king of Denmark and Norway, and prepared to enforce his claim. But he had reckoned without his host, when he supposed that the Swedes would support him in this enterprise. The Swedish nobility, which possessed greater power than the king, had long been dissatisfied with Albrecht, because he had surrounded himself with Germans, to whom he had given fiefs and posts of honor. They had long desired to rid themselves of him, and when Margaret made overtures to them, they seized the opportunity to accomplish their purpose. In February, 1389, Albrecht had to confront a united Swedish, Danish, and Norwegian army. The battle, fought at Falköping, in Vestergötland, was fraught with great results. Albrecht, who was unacquainted with the region, ventured with his heavy cavalry out upon a frozen marsh, fell through, and was taken prisoner. Margaret had him now in her power and determined to make him pay the penalty for the liberty he had taken with her name. Instead of the crown of Denmark, which he had meant to wear, she put upon his head a fool's cap with a tail 28 feet long, and mocked him mercilessly. He was then imprisoned in the castle of Lindholm, in Skaane, where he spent six years.