The new king of Bernicia, Eanfrith, was also killed by Cadwallon when the former went to him in an attempt to negotiate peace. However, Cadwallon was defeated by an army under Eanfrith's brother, Oswald, at the Battle of Heavenfield, "though he had most numerous forces, which he boasted nothing could withstand". Cadwallon was killed at a place called "Denis's-brook".
