Malcolm is Duncan’s eldest son. Almost captured in the battle that rages at the beginning of the play, he is rescued by the captain.
He is named Prince of Cumberland and heir to the throne by Duncan once all the fighting is done. On his father’s death, he flees to England, unwilling to trust the Scottish nobles. This allows Macbeth to frame him as the murderer. In time he becomes the rallying point of opposition to Macbeth, and with the English king’s help assembles a massive army to recover his throne. To test Macduff’s loyalty to Scotland, Malcolm pretends to be a thoroughly vile human being to him; he is reassured that Macduff works for his country and not simply out of hatred when Macduff turns from him. He conceives the idea of camouflaging his army’s advance with the trees of Birnam Forest. On his victory, he re-titles the thanes as earls, an English title rather than a Scottish one.