Macbeth is the protagonist of the play: a Scottish commander, Thane of Glamis and kinsman of King Duncan, who after hearing the witches kills the king, becomes king himself, and ends up killed by Macduff.
Before meeting the witches, he appears only covered in glory. In Act I, scene 2, a wounded Captain tells how the brave Macbeth, who deserves that name, defeated the rebel Macdonwald. Duncan, condemning the traitor Thane of Cawdor to death, passes the title to Macbeth: what Cawdor lost, the noble Macbeth has gained.
On the heath, the witches greet him as future king, and soon he speaks of a thought that entertains a murder that is no more than a fantasy. He sees a dagger in the air (Act II, scene 1), kills Duncan, and lives in fear: he hears that he will sleep no more, and as king he orders Banquo and his son Fleance killed. In Act IV, after the apparitions, he decides that the first impulses of his heart will also be the first impulses of his arm, and he orders the massacre of Macduff's family.
In Act V, he is without his wife, the lords are fleeing, and he is surrounded at Dunsinane. He kills young Siward, refuses to surrender to Macduff ("I will not yield!"), and fights to the end. Macduff returns with his head.