As any parish priest will tell you, the first step in repentance and reconciliation is a recognition that you have done wrong. When, in 651, Oswine of Deira was betrayed into the hands of his enemy, Oswiu of Bernicia, and was put to death, Oswiu was left in little doubt about the sinfulness of such an action, for, if Bede is to be believed, the killing was met with universal disgust. Oswiu might, I think, have been forgiven had he at first wondered why his action provoked such horror. After all, Oswine was not trying to make peace when he was killed. Even Bede, who condemns the murder, admits that Oswine was lying low, awaiting an opportune time to re-open hostilities.