With the year 1277 war commences between Sweden and Denmark. Magnus invades Halland and Scania, while Valdemar, with a Danish army, enters Smaland, burning the town of Vexio. With King Eric, Valdemar enters West Gothland, capturing Skara. At last the Danes are defeated at Ettak. Early in 1278 peace is made at Laholm, Magnus promising to pay his debt to Eric, leaving the castle of Lœdœse as security. Each promises not to shelter the rebels against the other. Valdemar lost his cause and had to give up Gothaland and his royal title, keeping only his inherited estates. On account of his scandalous living, the nobles insisted upon his imprisonment, and ten years after his abdication he was placed in custody at the castle of Nykœping. He survived all his brothers, dying in 1302. His son Eric was imprisoned at the castle of Stockholm, receiving good treatment like his father. When his cousin Birger was crowned, in 1302, he was set free, spending the rest of his life in Sweden as a private citizen. During Magnus Ericsson’s minority he was a member of the king’s council. When Magnus was sole occupant of the throne he took the title of “King of the Swedes and Goths,” which, occasionally used before, henceforward became the customary one.
A revolt against King Magnus took place shortly after the meeting at Laholm. Some of the nobles were dissatisfied with the favoritism shown foreigners, a complaint which was only too often justifiable, and forever repeated, in the course of centuries, against the Swedish monarchs. Count Gerhard of Holstein was imprisoned, and the Danish knight, Ingemar, killed. The king invited the rebels to him at Gællqvist, where he in an unexpected way made them prisoners, and had them beheaded, in August, 1280, confiscating their property. This incident is characteristic of the time, but there is no other authority for it than the Chronicle. The reign of Magnus was comparatively short, but a happy and glorious one. The relations with the island of Gothland were made closer and more intimate, although the proud independence of its inhabitants remained largely intact. They were to pay increased scat, but continued their government without royal officials. The Guts were of Swedish origin, and their island formed since the ninth century a part of Sweden, but their isolated position and great commercial activity made them almost independent. About the year 1000 they seek for themselves protection from the Swedish king, and after their baptism they turn to the bishop of Linkœping for spiritual guidance. Thanks to its position, halfway between Germany, Russia and Sweden, Gothland gives rise to the most important commercial centre of Northern Europe after Lubeck. The inhabitants of Visby were Germans, to a great extent, and their conflicts with the rural population were frequent. King Magnus appears as an arbitrator in such cases with an authority great enough to impose his conditions. In spite of the inimical relations between Denmark and Norway, Magnus held peace with both.