The Story of Norway by Hjalmar Hjorth Boysen

The Yngling race traced its ancestry from the god Frey. Snorre Sturlasson, in his famous work, "The Sagas of the Kings of Norway,"[A] mentions a long line of kings who were descended from Fjoelne, a son of Frey, and reigned in Sweden having their residence in Upsala. Yngve was one of the god's surnames, and Yngling means a descendant of Yngve. One of the Ynglings, named Aun the Old, sacrificed every ten years one of his sons to Odin, having been promised that for every son he sacrificed, ten years should be added to his life. When he had thus slain seven sons, and was so old that he had to be fed like an infant, his people grew weary of him and saved the eighth son, whom he was about to sacrifice. Ingjald Ill-Ruler, when he took the kingdom on the death of his father Anund, sixth in descent from Aun the Old, made a great funeral feast, to which he invited all the neighboring kings.

When he rose to drink the Brage goblet,[B] he vowed that he would increase his kingdom by one half toward all the four corners of the heavens, or die in the attempt. As a preliminary step he set fire to the hall, burned his guests, and took possession of their lands. When he died, about the middle of the seventh century, he was so detested by his people that they would not accept his son, nor any of his race, as his successor. The son, whose name was Olaf, therefore gathered about him as many as would follow him, and emigrated to the great northern forests, where he felled the trees, gained much arable lands, and thereby acquired the nickname The Wood-cutter. [C] He and his people became prosperous, and a great influx of the discontented from the neighboring lands followed. In fact, so great was the number of immigrants that the country could not feed them, and they were threatened with famine.