On the other hand, Kantorowicz says, Frederick was no "enlightened and tolerant potentate"—in fact he was "probably the most intolerant emperor that ever the West begot". Frederick terms himself the "God of vengeance who punishes the guilt of heretics to the second generation", and his "Liber Augustalis" begins with the proscription of heresy as treason punishable by death. At the Battle of Parma, "frightful necessity" drives him to a "reign of terror".