He was the son of Ealdred, and the grandson of Oswulf I[1] and was father of Uhtred the Bold, Ealdorman of Northumbria.
In 1006 Malcolm II of Scotland invaded Northumbria and besieged the newly founded episcopal city of Durham.
At that time the Danes were raiding southern England and King Æthelred was unable to send help to the Northumbrians.
Waltheof's son Uhtred, acting for his father, called together an army from Bernicia and Yorkshire and led it against the Scots.
Uhtred was rewarded by King Æthelred II with the ealdormanry of Bamburgh even though his father was still alive.