The ancestry of Uhtred the Bold can be found here:
https://en.wikipedia.org/wiki/Rulers_of_Bamburgh
This gives Uhtred the son of Waltheof I, c920 - 995, son of Ealdred, son of Oswulf I, c946 to after 954, son of Eadwulf I “King of the Northern English” d 913, son of Æthelthryth, who was the daughter of Ælla, King of Northumbria. Oswulf and Ealdred are reversed on the geni.com lineage. After Eadwulf I a whole list of people going back to Ida are listed which may be erroneous. Eadwulf I, "King of the Northern English," on Wikipedia is given as the son of Æthelthryth, daughter of Ælla, King of Northumbria here: https://en.wikipedia.org/wiki/%C3%86lla_of_Northumbria#:~:text=%C3%....
The ancestry of Ælla is not known.
