Olaf the Glorious A Story of the Viking Age by Leighton, Robert, -1934

So Olaf departed, ere yet he had broken bread, and he went north into Viken, while Queen Sigrid the Haughty went east into Sweden.

King Sweyn Forkbeard of Denmark had by this time regained full possession of his kingdom, and was contemplating an invasion of England which should be more complete and decisive than the attempt which he had made in company with the viking whom he had known as Ole the Esthonian. Sweyn had now, of course, discovered that this man Ole and King Olaf of Norway were one and the same person, and he began to be very jealous of the glory that was gathering about Olaf's name. A new cause for jealousy had now arisen.

Sweyn, it will be remembered, had married the Princess Gunnhild, daughter of Burislaf, King of the Wends. But in these days even now told of it befell that Queen Gunnhild was stricken with an illness and died. King Sweyn, ever ambitious of winning great dominion, had a mind to take unto himself a new wife in the person of Queen Sigrid of Sweden. He was on the point of setting out to woo her when he heard by chance that King Olaf Triggvison was already bent upon a similar journey. Envy and jealousy and bitter hatred welled up in Sweyn's breast against his rival, and he swore by Thor's hammer that sooner or later he would lower King Olaf to the dust.

But in good time King Sweyn heard of the quarrel that had befallen between Queen Sigrid and her young Norwegian suitor. So he at once fared north into Sweden to essay his own fortune with the haughty queen. He gained a ready favour with Sigrid by speaking all manner of false and malicious scandal against the man whom she had so lately rejected. Sigrid probably saw that by marrying the King of Denmark she might the more easily accomplish her vengeance upon Olaf Triggvison. She therefore accepted Forkbeard's proposals, and they were wedded in accordance with the rites and customs of their pagan faith.

Earl Erik, the son of the late Earl Hakon, was at this time the guest and friend of Sigrid's son, Olaf the Swede King; and these three--King Sweyn Forkbeard of Denmark, King Olaf of Sweden, and Earl Erik of Lade--had each a private cause of enmity against Olaf Triggvison. It was they who, two years afterwards, united their forces in the great sea fight in which Olaf the Glorious lost his life.

CHAPTER XVIII: THE "LONG SERPENT".