In order to kill in self-defence [in Medieval England], it was necessary for the man attacked to retreat until retreat was no longer possible. At the trial the jurors always alleged the presence of such an impasse, and though that was sometimes true, a comparison of the coroners’ rolls and the trial rolls reveals that it often was not and that a petty jury had so altered the facts as to make pardonable what the law considered nonpardonable. From the community’s point of view, a violent attack could be met by a violent response. A man whose life was threatened did not have to seek some means of escape; indeed, he need not do so though he was not in danger of losing his life. The court’s concern with last resort indicates a concept of criminal liability fundamentally at odds with prevailing social notions.
Thomas A. Green, “Societal Concepts of Criminal Liability for Homicide in Mediaeval England” (1972)