The war was still continued for three years with changing fortunes. In fact, Magnus, whenever he returned from Denmark, where he sojourned in the intervals between his defeats, seemed as formidable as ever, and had little difficulty in gathering an army under his banner. Sverre, therefore, in order to put an end to an internecine conflict which was draining the resources of the country, proposed to share the kingdom with him, and, when this proposal was rejected, that they should reign alternately for a term of three years each. This well-meant offer Magnus likewise repelled, and, after repeated interviews and fruitless negotiations, hostilities were resumed. Three times during the years 1181 and 1182 the Heklungs attacked Nidaros, where the Birchlegs had their head-quarters, and fought with variable success. In 1183 Sverre assumed again the offensive, surprised Magnus in Bergen, and compelled him to flee to Denmark, abandoning his fleet, his treasures, and the crown regalia. Archbishop Eystein, who had been one of the staunchest partisans of the Heklungs, had, some years before, fled to England, and had hoped to injure Sverre by declaring him in the ban of the church. Sverre was, however, not in the least disturbed by the ban, while the archbishop was greatly disturbed by the loss of his see. Perceiving that Magnus' chances of regaining his power were diminishing, the wily prelate opened negotiations with the excommunicated king and received him back into the bosom of the Church, on condition of being restored to his dignities.