Question: When did Osthryth's father die?
Sentence (from "Oswiu"): Oswiu, also known as Oswy or Oswig  (c. 612 – 15 February 670), was King of Bernicia from 642 and Northumbria from 654 until his death, and is most notable for his role at the Synod of Whitby in 664.
Relevant evidence: Yes