Meantime, some of the Danes who were most stubborn in their hatred against Ragnar were obstinately bent on rebellion.  They rallied to the side of Harald, once an exile, and tried to raise the fallen fortunes of the tyrant.  By this hardihood they raised up against the king the most virulent blasts of civil war, and entangled him in domestic perils when he was free from foreign troubles.  Ragnar, setting out to check them with a fleet of the Danes who lived in the isles, crushed the army of the rebels, drove Harald, the leader of the conquered army, a fugitive to Germany, and forced him to resign unbashfully an honour which he had gained without scruple.  Nor was he content simply to kill his prisoners:  he preferred to torture them to death, so that those who could not be induced to forsake their disloyalty might not be so much as suffered to give up the ghost save under the most grievous punishment.  Moreover, the estates of those who had deserted with Harald he distributed among those who were serving as his soldiers, thinking that the fathers would be worse punished by seeing the honour of their inheritance made over to the children whom they had rejected, while those whom they had loved better lost their patrimony.  But even this did not sate his vengeance, and he further determined to attack Saxony, thinking it the refuge of his foes and the retreat of Harald.  So, begging his sons to help him, he came on Karl, who happened then to be tarrying on those borders of his empire.  Intercepting his sentries, he eluded the watch that was posted on guard.  But while he thought that all the rest would therefore be easy and more open to his attacks, suddenly a woman who was a soothsayer, a kind of divine oracle or interpreter of the will of heaven, warned the king with a saving prophecy, and by her fortunate presage forestalled the mischief that impended, saying that the fleet of Siward had moored at the mouth of the river Seine.  The emperor, heeding the warning, and understanding that the enemy was at hand, managed to engage with and stop the barbarians, who were thus pointed out to him.  A battle was fought with Ragnar; but Karl did not succeed as happily in the field as he had got warning of the danger.  And so that tireless conqueror of almost all Europe, who in his calm and complete career of victory had travelled over so great a portion of the world, now beheld his army, which had vanquished all these states and nations, turning its face from the field, and shattered by a handful from a single province.

Ragnar, after loading the Saxons with tribute, had sure tidings from Sweden of the death of Herodd, and also heard that his own sons, owing to the slander of Sorle, the king chosen in his stead, had been robbed of their inheritance.  He besought the aid of the brothers Biorn, Fridleif, and Ragbard (for Ragnald, Hwitserk, and Erik, his sons by Swanloga, had not yet reached the age of bearing arms), and went to Sweden.  Sorle met him with his army, and offered him the choice between a public conflict and a duel; and when Ragnar chose personal combat, he sent against him Starkad, a champion of approved daring, with his band of seven sons, to challenge and fight with him.  Ragnar took his three sons to share the battle with him, engaged in the sight of both armies, and came out of the combat triumphant.