It is not perfectly clear whether Sweyn accepted this challenge, though there is a probability that he did, as Harold would scarcely otherwise have gone to the place appointed for the battle. As on the former occasion, however, he waited in vain for the foe, and, dismissing the greater part of his force, sailed with one hundred and eighty ships down along the coast of Skaane until he came to Nis-aa, where he was surprised by Sweyn with a fleet of three hundred and sixty ships. A bloody battle was fought, lasting through an entire night (1062), and ending with the complete rout of the Danes. The victory was in a large measure due to the Norse chieftain Haakon Ivarsson, a man whom Harold had treated with harshness, but who, in the king's need, nevertheless, came to his rescue. Sweyn, too, owed his safety to Haakon, on board whose ship he sought refuge, and by whose aid he made his escape. Great as the victory at Nis-aa was, its results, as far as Harold was concerned, proved insignificant. It was vain to suppose that Sweyn, as long as he had any power of resistance, would renounce his throne; and even if he had been willing to abide by such an agreement, the Norsemen's many plundering expeditions had made them so hated in Denmark that an army of occupation would have been needed to keep the land under their sway. They were, however, no less weary than the Danes of the incessant hostilities, and much against his will, Harold was forced to make peace at Götha Elv in 1064. He recognized Sweyn as king of Denmark, and promised no more to molest him. The excessive burdens which Harold had imposed upon his people, in order to obtain the means to carry on this war, had produced great discontent among the peasants, and the important domestic events which preceded the peace will now claim our attention. During the prosecution of the war nothing irritated the king more than the captious criticism and opposition of the chieftains, and particularly of their leader, Einar Thambarskelver. Einar, with his six hundred men-at-arms, following him wherever he went, was the personified defiance of the king's authority; and Harold, when he once saw him land at the pier in Nidaros, flaunting his power in his face, is said to have exclaimed in verse: "Here I must see the haughty Einar land with a band of _hus-carles_ so large that many an earl would have been satisfied with less. He thinks, perhaps, himself to mount the throne; and he will not stop until he has deprived me of my kingdom, unless he has first to kiss the thin lips of the axe."