Erling Skakke considered it a policy of necessity to remove any person who by reason of royal birth might become rivals of his son to the throne. King Sigurd Mund had left a daughter named Cecilia. As soon as she became old enough, he sent her to Vermeland and made her the mistress of Folkvid the lawman, knowing that the children from such a connection could not become dangerous rivals. About the same time one of the king's men discovered and brought to Erling a young man named Harald, who in all secrecy had been brought up in the Uplands. He was the son of Erling's own wife Kristina, and his father was the late King Sigurd Mund. An illicit intimacy between such near relatives as Kristina and Sigurd was, under the church laws of the time, considered one of the greatest sins, and everything had therefore been done to keep the matter secret, and Kristina had heretofore succeeded in concealing her guilt. When Erling saw the illegitimate son of his wife before him, he said very little, and those present understood that the young man was doomed. King Magnus, who had taken a liking to Harald, interceded in his favor; but his father answered: "Thou wouldst govern this kingdom but a short time in peace and safety, if thou wert to follow the counsels of the heart only." Earl Erling ordered Harald to be taken to Nordnes, where he was beheaded. Erling Skakke, however, did not succeed in removing all pretenders. In the year 1174 there appeared on the scene a young man called Eystein, who claimed to be a son of King Eystein Haraldson. He was small of stature, and had a fine, soft face, and he was therefore generally called Eystein Meyla (Little Maiden). He first went on a visit to Gautland to Earl Birger Brosa, who was married to Eystein's aunt, Brigida, a daughter of Harald Gille. They received him well, and furnished him some assistance in men and money. Eystein then proceeded to Norway, and when he came to Viken many people flocked to him. His followers proclaimed him king, and he remained in Viken during the winter. His means of subsistence being soon exhausted, they commenced to rob and steal wherever there was an opportunity. They were not strong enough to remain long in any one place, but roamed about in mountains and forests. They suffered great hardships. Their clothes being worn out, they wound the bark of the birch-tree about their legs, and therefore the people called them Birkebeiner (_i.e._, Birchlegs). During the two years which the Birchlegs spent in and about Viken (1174-76), they had three battles in regular array with the peasants, and were victorious in them all; but at Krokaskog they came near meeting a disaster in encountering a superior force, and they only saved themselves by a hasty flight.