Brusi was unable to resist the great power of Thorfinn, so he resolved to go east to Norway, and ask Olaf the king to do justice between him and his brother. Thorfinn also went to Norway to plead his own cause. King Olaf, unwilling to increase the power of a subject already too powerful, decided in favour of Brusi. But when the two earls returned to the islands, Brusi found the task of ruling his dominions and defending them against the Vikings too heavy for him, and Thorfinn no doubt took care that there should always be plenty of trouble for him to face. At last Brusi was glad to hand over two-thirds of the earldom to Thorfinn, on condition of his undertaking to defend the islands; and this arrangement lasted till Brusi’s death. In the meantime, Rognvald, Brusi’s son, had been growing up at the Court of Olaf, King of Norway, and he was a close friend of Magnus, Olaf’s son, who afterwards became king. When Rognvald heard that Brusi, his father, was dead, and that Earl Thorfinn had seized the whole earldom, he prepared to fare westward and claim his share of the land. Thorfinn was now the most powerful ruler in all the western lands. He had defeated the Scots in a great sea-fight off Deerness; he had subdued the Western Isles; he had conquered great realms in Scotland; and he had made himself master of the half of Ireland. At the time when Rognvald came to the Orkneys, however, Thorfinn had wars on his hands in the Western Isles and in Ireland, and he was glad to offer Rognvald two-thirds of the islands in return for his friendship and his help. So for a time the two earls lived in friendship with each other. Then evil men made mischief between them, and Thorfinn demanded back the third of the land which had belonged to Earl Einar. Rognvald refused, and sailed away to Norway to ask help from King Magnus. With a fleet of Norwegian ships he came back to Orkney, and was met in the Pentland Firth by the ships of Earl Thorfinn. Earl Rognvald’s ships were fewer in number, but their larger size at first gave him the advantage. Earl Thorfinn was hard pressed; but at last he persuaded his brother-in-law, Kalf Arnesson, whose ships were lying by watching the fight, to come to his aid and row against Rognvald. Then the tide of battle turned against Earl Rognvald, and only by the darkness of the night was he enabled to escape, and once more to find his way to Norway.