He was captured during the course of the Norman conquest of England, and imprisoned in Normandy, being released only at the death of William the Conqueror.
[2] Most historians believe Edith Swan-neck was Ulf's mother,[3][4][5][6][7] but in the 19th century Edward Freeman argued that it was Ealdgyth.
If Freeman was correct then Ealdgyth must have given birth to Ulf in Chester after Harold's death, having been married to him for only a few months in total, and since she was also the mother of a son called Harold that would necessarily imply that the two boys were twins.
[4] At some point in William the Conqueror's reign, perhaps during the period of confusion after the Battle of Hastings, Ulf was taken prisoner and moved to Normandy, where he remained until 1087.
[9] When William was on his deathbed he was persuaded by the church dignitaries in attendance on him to release all of his political prisoners, Ulf among them.