Macbeth is a political play. It dramatizes a story about power and authority, about order and disorder, about the violence of civil war and the final restoration of peace. At the center of all these concerns lies the issue of kingship in its legitimate and illegitimate forms, including succession, the rightful transition of authority from one ruler to the next; regicide, the killing of the king; usurpation, the wrongful seizure of the crown; and tyranny, the cruel abuse of power by a state ruler. Questions about the proper exercise of power directly involve everyone on stage. In the course of the play, no less than three Scottish kings wear the crown: Duncan, Macbeth, and Malcolm. The English king Edward the Confessor is also mentioned with approval, and Banquo receives the politically confusing promise that he will father many kings. All the other characters, even the witches and Lady Macbeth, act either to make a king, to support and protect him, or to destroy him. There are no subplots and few digressions from this focus. Perhaps the simplicity of the plot contributes to its appeal. Many have gone so far as to say that the world vision in Macbeth is black and white because the conflict between good and evil is clearly defined.