Question: What Brittonic dialect was spoken in the kingdom who had the father of Owain mab Urien as king?
Sentence (from "Owain mab Urien"): Owain mab Urien (or Owein) (died c. 595) was the son of Urien, king of Rheged c. 590, and fought with his father against the Angles of Bernicia.
Relevant evidence: Yes