Question: Which battle taking place in 7th century England was the result of peace overtures from Augustine's English mission by the Synod of Chester where the armies of the combined Welsh kingdoms of Powys and Rhôs were virtually annihilated?
Sentence (from "Battle of Chester"): It resulted in the deaths of Welsh leaders Selyf Sarffgadau of Powys and Cadwal Crysban of Rhôs.
Relevant evidence: No