Jarl Ulf's sister, Gyda, was married to Jarl Gudin (Godwin) Ulfnadson; and their sons were, Harald King of England, and Jarl Tosti, Jarl Walthiof, Jarl Mauro-Kaare, and Jarl Svein.

Gyda was the name of their daughter, who was married to the English King Edward, the Good (whom we call the Confessor).
"When they had played a while, the King made a false move; on which the Jarl took a knight from him; but the King set the piece on the board again, and told the Jarl to make another move.

But the Jarl flew angry, tumbled the chess-board over, rose, and went away.

The King said, 'Run thy ways, Ulf the Fearful.' The Jarl turned round at the door and said, 'Thou wouldst have run farther at Helge river hadst thou been left to battle there.

Thou didst not call me Ulf the Fearful when I hastened to thy help while the Swedes were beating thee like a dog.' The Jarl then went out, and went to bed.
"The following morning, while the King was putting on his clothes, he said to his footboy, 'Go thou to Jarl Ulf and kill him.' The lad went, was away a while, and then came back.