How did Macbeth earn the respect of King Duncan in Act One?
Macbeth earns the respect of Duncan through his prowess on the battlefield. Duncan is facing an uprising by the rebel Macdonwald as well as a Norwegian invasion, and Macbeth and Banquo lead his forces against them. Duncan learns from a Sergeant returning from the fray that Macbeth met Macdonwald on the field and "unseam'd him from the nave to the chaps, And fix'd his head upon our battlements." Then Macbeth and Banquo defeated the Norwegian king, who had taken advantage of the internal strife by launching an invasion. Duncan responds to the Sergeant's account of the battle by exclaiming that Macbeth is his "valiant cousin" and a "worthy gentleman." The king then rewards his kinsman's loyalty and valor by naming him Thane of Cawdor, replacing the former holder of that title, who would be executed for his role in the rebellion. Macbeth's portrayal in this scene as a valiant, loyal thane makes his degeneration into a murderous, scheming monster late in the play all the more dramatic.