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 "Synod of Chester"): The period is known from only a few surviving sources, so dates and accounts vary, but it seems to have been a major event in the history of Wales and England, where the native British bishops rejected overtures of peace from Augustine's English mission.
Relevant evidence: Yes