Eysteinn Beli or Eysteinn inn illráði, Swedish: Östen Illråde (ill-ruler) or Östen Beli, was a legendary king of Sweden who would have ruled in the late 8th century.
According to Krákumál (stanza 7), he fell at Ulleråker south of Uppsala.
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. Ivar the Boneless, the leader, then settled at Lejre with his brothers.
Ragnar was jealous with his sons' successes, and set Eysteinn as the jarl of Sweden, telling him to protect Sweden from his sons. He then went east across the Baltic Sea to pillage and to show his own skills.
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 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.
Eysteinn offered Eric as much of Uppsala öd as he wanted, and Borghild, in wergild for Agnar. Eric proclaimed that after such a defeat he wanted nothing but to choose the day of his own death. Eric asked to be impaled on spears that raised him above the dead and his wish was granted.
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. Aslaug, calling herself Randalin rides with cavalry across the land.