A fertile cause of disagreement among Harold's sons was their jealousy of Erik, whom their father conspicuously favored. When he was twelve years old, Erik was given five ships to command, and with a choice crew went on viking cruises. Much did the old king delight in hearing the tales of his prowess, and the daring enterprises in which he had played a part. The ominous surname "Blod-Oexe" (Blood-Axe) which the lad acquired by his deeds in battle only endeared him the more to his father. It was his love of this favorite son which induced him in his fiftieth year (900) to commit an act, whereby he virtually undid the great work of his life and brought misery upon unborn generations. He called a _thing_ or general assembly of the people, probably at Eidsvold, and made all his sons kings, on condition that they should, after his death, acknowledge Erik as their overlord. To each he gave a province to govern, permitting him to keep one third of the revenues for himself, leaving one third for the earls, and sending one third to the sovereign. The royal title should be inherited by all his direct descendants in the male line, legitimate or illegitimate birth making no difference. To the sons of his daughters he gave earldoms. In this disastrous act of Harold, making no distinction between legitimate and illegitimate children, lies the germ of the civil wars and terrible internecine conflicts which ravaged the kingdom he had established and exhausted its powers, until for four hundred years it sank out of sight, and its name seemed to have been blotted out from among the nations. It seems incredible that the wisdom and energy which had built up a great state could be coupled with the unwisdom and the weakness which in the end broke it down again. Harold evidently looked upon the royal office as a piece of personal property which he had by his sword acquired, and which all his male descendants had an equal right to inherit. At the same time he must, after the experience he had had with his sons, have known them too well to suppose that they would peacefully acquiesce in his decision, living together in fraternal unity. If he cherished any illusion, Erik lost no time in dispelling it. He first killed Ragnvald Rettilbeine, the son of Snefrid, because he was said to be a sorcerer. Next he attacked his brother Björn the Merchant (Farmand) because he declined to pay him tribute, killed him and plundered his house. Halfdan the Swarthy (Svarte) in Drontheim resolved to avenge this outrage, concluding that none of Harold's sons were safe, as long as Erik was permitted, with impunity, to take the law into his own hands. While Erik was feasting at the farm, Selven, Halfdan surrounded the house and set fire to it. Erik succeeded in escaping with four men, and he hastened southward to complain to his father. King Harold, it is told, was greatly incensed, collected his fleet and sailed to Drontheim, where