Complex sentence: According to Västgötalagen Ragnvald's decision was taken as an insult to the people of Västergötland, since it showed that he did not fear them, and they killed him in Karlepitt (an unknown location in Västergötland).
Split into simpler sentences: According to Västgötalagen was Ragnvald's decision taken as an insult to the people of Västergötland, as he showed that he did not fear them. The people of Västergötland took however advantage of this and killed him in Karlepitt (an unknown location in Västergötland).