https://en.wikipedia.org/wiki/Waltheof_of_Bamburgh

Waltheof was high-reeve or ealdorman of Bamburgh . He was the son of Osulf I and father of Uhtred the Bold, Ealdorman of Northumbria. His name is Scandinavian and implies that he had Viking ancestors.

The name 'Waltheof' remained in his family when Earl Siward married his great-granddaughter and named his son Waltheof. This son of Siward became Waltheof, Earl of Northumbria, and one of his descendant being Saint Waltheof of Melrose.

Additionally, another branch of the family would use the Waltheof name including: Waltheof of Allerdale who was son of Gospatric, Earl of Northumbria. Waltheof of Inverkeithing and Dalmeny was son of Cospatric, and grandson of Waltheof of Allerdale. Another descendant of Gospatric, Earl of Northumbria was Waltheof, Earl of Dunbar

Genealogical research provides a thesis that there is a high probability that Waltheof de Strachan is likely descendant from this line as well. Walthoef de Strachan is the progenitor of Clan Strachan.

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 Ethelred was unable to send help to the Northumbrians. Ealdorman Waltheof was too old to fight and remained in his castle at Bamburgh. Ealdorman Ælfhelm of York also took no action. Waltheof's son Uhtred, acting for his father, called together an army from Bernicia and Yorkshire and led it against the Scots. The result was a decisive victory for Uhtred. Local women washed the severed heads of the Scots, receiving a payment of a cow for each, and the heads were fixed on stakes to Durham's walls. Uhtred was rewarded by King Ethelred II with the ealdormanry of Bamburgh even though his father was still alive. .