Einar seized Somerled's share, and maintained possession by force of arms. Thorfinn immediately laid claim to Somerled's possessions as his right, but the claim, though conceded by Brusi, was disregarded by Einar. Einar is described as constantly aspiring after vast objects, stern in countenance, harsh in speech, unrelenting in nature, and ever ready to undertake the most perilous deeds. His numerous warring expeditions were not always successful, so the heritable odallers suffered severely from his exactions, and, contrasting their condition with that of those under the government of Earl Brusi, whose disposition was similar to that of Somerled, they at last resolved to seek the interposition of Amundi, a noble in high esteem with the Earl. Amundi listened to their solicitations with attention, and would gladly have acted as mediator between the oppressed Orcadians and their Lord, but, knowing the disposition of the Earl, he felt that he would only become a target for his vengeance, nor was there any likelihood of a petition resulting in the mitigation of their distress. He therefore declined the dangerous office. The odallers then transferred their solicitations to Amundi's son, Thorkell, who was the most accomplished person in the Isles. Their importunings were so continuous that he at last undertook to approach the Earl on their behalf. So, at the next Thing meeting [general assemblage of Free men], Thorkell begged the Earl to spare the people, and told him of their distress. Einar answered blandly, and said he would give great weight to Thorkell's words, but warned him not to again address him on such a matter. "I had intended", he said, "to take out six ships, but shall now not take more than three; but thou, Thorkell do not ask me this a second time".
The following spring, Earl Einar resolved to make up for his disadvantage of the past year, by an increased naval armament, much to the dismay of his people, who, taking heart from Thorkell's former success, implored him to again act as mediator for them, and he, yielding to their entreaties, undertook to do so. On this occasion, however, the Earl would not listen to him, and became very wroth. Amundi advised his son to avoid the impending storm, and go abroad. Thorkell accordingly crossed the Pentland Firth, and took refuge in Caithness with Earl Thorfinn. He stayed there a 1ong while, and became foster-father to the latter Earl, who was still young. From that time he was called Thorkell the Foster, and became a man of great repute.
When Thorfinn attained his majority he re-demanded the third of the Islands, being his share, but Einar, disinclined to divide his possessions, prepared to resist the claim. Tborfinn thereon called his people to arms, and set sail for Orkney. Einar at once collected an army to defend the Isles, and Earl Brusi also gathered his forces and went to meet them, in the hope of effecting a reconciliation, and peace was made on condition that Thorfinn should receive his third. Thorfinn appointed deputies to manage his possessions in the Isles, and lived for the most part in Caithness.
Brusi and Einar now entered into a compact, joining their portions, which Einar was to rule and defend for both, and he who survived the other should inherit his portion. This compact was generally viewed as unfair, for Brusi had a son, Rognvald, while Einar had no son.
In the summer Einar went on expeditions to Ireland, Scotland, and Wales. One summer when ravaging Ireland, he fought in Lough Larne (Ulreksfiord) with O'Connor (Conchobhar), an Irish king, and was defeated with a heavy loss of men. He attributed this loss chiefly to the Norwegian troops that fought under O'Connor, and were commanded by Eyvind Uravhorn, an officer in the life-guards of King Olaf Haraldson, surnamed the Holy. The next summer Eyvind, when sailing from Ireland for Norway, being overtaken by a gale, sought shelter in Osmundwall, now known as Longhope. This coming to the knowledge of Earl Einar, he mustered his men, went thither and executed Eyvind, but gave quarter to most of his followers, whom he allowed to continue on their voyage to Norway. When they related the circumstance to King Olaf, he said very little at the time, but it turned out afterwards he was highly offended.
About this time Earl Thorfinn sent Thorkell to Orkney to collect his rents. While in the Isles, Thorkell received word that Einar resented his presence, and. was compassing his death, alleging that it was owing to his instigation that Thorfinn had obtained the third part of Orkney. Thorkell therefore hastily concluded his affairs and re-crossed the Firth, on his return acquainting Thorfinn of what he had heard. He further stated his intention of going over-sea to some remote country, where though an exile he would be free from danger. Thorfinn approved of his resolution, and, assuring him of his regard, suggested Norway as a place equally convenient and honourable for that purpose. So in the autumn Thorkell went to Norway, where he was presented to King Olaf, with whom he became such a favourite that he was made one of the Privy Council, and spent the winter in great friendship with the king. Early in the spring King Olaf sent a ship for Earl Thorfinn, inviting him in the most friendly manner to come to Norway. Thorfinn promptly accepted the invitation, and went east at once, where he spent most of the summer season. At his departure King Olaf presented him with a stately war-galley, fully equipped; while Thorfinn transferred his own to Thorkell Foster, who was determined to return with him. Landing in Orkney in the autumn, they found that Einar had gathered his forces to oppose them. Brusi again came to the rescue, and effected a second reconciliation, and the peace was confirmed by oaths. Thorkell should be pardoned and restored to favour with Earl Einar, and the friendship was to be sealed by mutual entertainments. Thorkell banqueted the Earl in his hall at Sandwick in Deerness, but it was observed that although Einar and his men were most sumptuously treated, he continued sullen throughout. When the feast was over it became Thorkell's turn to accompany the Earl to be similarly treated in return; but from the Earl's manner Thorkell thought it prudent to delay the event as long as possible. Meantime it was discovered that along the intended route there were three divisions of armed men in ambush. Certain that foul play was intended, he took the initiative and slew the Earl. Einar was sitting down, and asked Thorkell if he were ready for the journey. Thorkell answered, "I am ready now", and, drawing his sword, dealt the Earl a fatal blow on the head, and then with Hallvard, an Eastfirth Icelander, and the rest of his party, made for their ships, in which they sailed directly for Norway, where he was well received by King Olaf, with whom he spent the winter. Earl Einar's men were stupefied by the suddenness of the deed, which they had not expected from Thorkell, and many of them being unarmed, and others his friends, enabled him to get away without opposition.