When the boys grew up, they went to Zealand, and were bidden by their friends to avenge their father.  They vowed that they and their uncle should not both live out the year.  When Ragnar found this out, he went by night to the palace, prompted by the recollection of his covenant, and announced that he was come privily to tell the king something he had promised.  But the king was asleep, and he would not suffer them to wake him up, because Frode had been used to punish any disturbance of his rest with the sword.  So mighty a matter was it thought of old to break the slumbers of a king by untimely intrusion.  Frode heard this from the sentries in the morning; and when he perceived that Ragnar had come to tell him of the treachery, he gathered together his soldiers, and resolved to forestall deceit by ruthless measures.  Harald’s sons had no help for it but to feign madness.  For when they found themselves suddenly attacked, they began to behave like maniacs, as if they were distraught.  And when Frode thought that they were possessed, he gave up his purpose, thinking it shameful to attack with the sword those who seemed to be turning the sword against themselves.  But he was burned to death by them on the following night, and was punished as befitted a fratricide.  For they attacked the palace, and first crushing the queen with a mass of stones and then, having set fire to the house, they forced Frode to crawl into a narrow cave that had been cut out long before, and into the dark recesses of tunnels.  Here he lurked in hiding and perished, stifled by the reek and smoke.

After Frode was killed, Halfdan reigned over his country about three years, and then, handing over his sovereignty to his brother Harald as deputy, went roving, and attacked and ravaged Oland and the neighbouring isles, which are severed from contact with Sweden by a winding sound.  Here in the winter he beached and entrenched his ships, and spent three years on the expedition.  After this he attacked Sweden, and destroyed its king in the field.  Afterwards he prepared to meet the king’s grandson Erik, the son of his own uncle Frode, in battle; and when he heard that Erik’s champion, Hakon, was skillful in blunting swords with his spells, he fashioned, to use for clubbing, a huge mace studded with iron knobs, as if he would prevail by the strength of wood over the power of sorcery.  Then—­for he was conspicuous beyond all others for his bravery—­amid the hottest charges of the enemy, he covered his head with his helmet, and, without a shield, poised his club, and with the help of both hands whirled it against the bulwark of shields before him.  No obstacle was so stout but it was crushed to pieces by the blow of the mass that smote it.  Thus he overthrew the champion, who ran against him in the battle, with a violent stroke of his weapon.  But he was conquered notwithstanding, and fled away into Helsingland, where he went to one Witolf (who had served of old with