Ragnar's sons Eric and Agnar then sailed into Lake Mälaren and sent a message to the Swedish King Eysteinn, a vassal of Ragnar, that they wanted him to submit to Ragnar's sons. Moreover, Eric said that he wanted Eysteinn's daughter Borghild as wife. Eysteinn said that he first wanted to consult the Swedish chieftains. The chieftains said no to the offer, and ordered an attack on the rebellious sons. A battle ensued and Eric and Agnar were overwhelmed by the Swedish forces, whereupon Agnar died and Eric was taken prisoner.