It would seem that Alfred’s chief troubles during the years following were caused by the fierce sons of Ragnar Lodbrog, brothers of Ivar the Boneless of Northumbria. These three brothers, Halfdene, Ivar, and Ubba, overran the whole country, appearing with great rapidity at different points, so that, as one historian says, they were no sooner pushed from one district than they reappeared in another. Alfred tried by every means to disperse the Danish army. He made them swear over holy relics to depart, but their promise was hardly given before it was broken again; he raised a fleet after their own pattern and attacked them at sea; and he laid siege to Exeter, where they had entrenched themselves, cutting off their provisions and means of retreat. It was like fighting a swarm of flies; however many were killed, more came overseas to take their place. “For nine successive years,” writes William of Malmesbury, “he was battling with his enemies, sometimes deceived by false treaties, and sometimes wreaking his vengeance on the deceivers, till he was at last reduced to such extreme distress that scarcely three counties, that is to say, Hampshire, Wiltshire, and Somerset, stood fast by their allegiance.” He was compelled to retreat to the Isle of Athelney, where, supporting himself by fishing and forage, he, with a few faithful followers, led an unquiet life amid the marshes, awaiting the time when a better fortune should enable them to recover the lost kingdom. One hard-won treasure they had with them in their island fortress. This was the famous Raven Banner, the war-flag which the three sisters of Ivar and Ubba, Lodbrog’s daughters, had woven in one day for their brothers. It was believed by them that in every battle which they undertook the banner would spread like a flying raven if they were to gain the victory; but if they were fated to be defeated it would hang down motionless. This flag was taken from the brothers in Devon at the battle in which Ubba was slain, and much booty with it. No doubt it was cherished as an omen of future victory by the followers of the unfortunate Alfred in their retreat.