Eysteinn beli

Eystein Beli is the king of Sweden in Ragnar's legend — first the great viking's ally, then his enemy, and the keeper of an uncanny guardian. He holds his realm under the protection of a magical sacrificial cow, Síbilja, whose bellowing maddens any army that comes against her, so that no foe can stand. When Ragnar's sons make war on him to avenge a wrong, it is the youngest who must contrive to overcome the monstrous cow before the king can be beaten. Eystein Beli belongs to the oldest, most marvel-filled layer of the legendary sagas, where kings keep enchanted beasts and battles turn on magic as much as on arms. He is the saga's image of the king guarded by sorcery — the Swedish ruler whose power rests on a bellowing magical cow, overthrown only when the spell that protects him is broken, a figure from the fairy-tale end of the Ragnar cycle.