The apparently oldest version, Ragnarssona þáttr, relates that Ragnar Lodbrok's sons had left Sweden and conquered Zealand, Reidgotaland (here Jutland), Gotland, Öland and all the minor islands.
Ragnar's sons Eric and Agnar then sailed into Lake Mälaren and sent a message to king Eysteinn that they wanted him to submit to Ragnar's sons, and Eric said that he wanted Eysteinn's daughter Borghild as wife.
Eysteinn offered Eric as much of Uppsala öd as he wanted, and Borghild, in wergild for Agnar.
In Zealand, his mother Aslaug and his brothers Björn Ironside and Hvitserk, who had been playing tafl, become upset and sail to Sweden with a large army.
As Ragnar understood that Kraka was of better descent than that of Ingeborg, he decided not to go back to Sweden and wed Eysteinn's daughter.
This was interesting news to Ragnar's sons Eric and Agnar who decided to go to Sweden and pillage, as their father would not mind anymore.
When Aslaug heard the news of Eric and Agnar's death, she cried blood, and asked Ragnar's sons to avenge their dead brothers.
Hvitserk and Björn Ironside mustered fourteen, while Aslaug and Ivar the Boneless marshalled ten ships each.
When the armies met in battle, Ivar told everyone to make such a din that the bellowing from Sibilja could not be heard.
It says that Ragnar Lodbrok's son Agnar learnt that his brother Eric had been slain by Osten, the king of Sweden.
Skáldatal says that Eysteinn Beli was the patron of many skalds, including Bragi inn gamli, Grundi prúði, Erpr lútandi, Kálfr þrænzki, Refr ryzki, Ormr oframi, two named Ölvaldi, Ávaldi, Fleinn skáld and Rögnvaldr skáld.