The account of the battle of Brunanburh in Egil’s Saga begins by describing the strong combination made against Athelstan by the princes of the north of England with the Scots and Welsh and the Irish Danes, of whom we have already spoken. They thought to take advantage of Athelstan’s youth and inexperience, for he was at this time only thirty years old. Olaf o’ the Sandal is here called Olaf the Red, which may have been the title by which he was known in Norway. He marched into Northumbria, “advancing the shield of war.” Athelstan, having laid claim to Northumbria, set over it two earls, Alfgeir and Gudrek, to defend it against the Irish and Scots, and they mustered all their forces and marched against Olaf. But they were powerless against his great army, and Earl Gudrek fell, while Alfgeir fled with the most part of his followers behind him. When Alfgeir reported his defeat to Athelstan he became alarmed, and summoned his army together; he sent messengers in every direction to gather fresh forces, and among those who heard that he wanted men and came to his assistance were the brothers Thorolf and Egil, who were coasting about the shores of Flanders. Athelstan received them gladly, for he saw that they were trained fighting-men and brought a good following; but he wished them to be “prime-signed,” in order that the Norse of his own army might fight on good terms with them. It was a custom in those days, when pagan men traded with Christian countries, or when they took arms for them, that they should allow themselves to be signed with the cross, which was called “prime-signing,” for then they could hold intercourse with Christians and pagans alike, though they did not thereby give up their pagan faith, and usually returned to their own worship when they went home to Norway or Iceland. Egil and Thorolf consented to this, for England was at that time a Christian country. They entered the King’s army, and three hundred men-at-arms with them.