A play about how dreams may become nightmares and how the world is turned upside-down, Macbeth begins and ends with violent action. In Act I the turbulence of war sets the stage for the maelstrom of emotions, preternatural creatures, the phantasmagoric, and even madness as King Duncan is at war with King Sweno of Norway as well as rebellious kinsmen. In Scene 2, set in a camp near Forres (a town in northeast Scotland), a sergeant returns from the field to report upon a violent battle in which the fearless Macbeth has vanquished "with bloody execution" the traitor Macdonwald. The ruthless warrior Macbeth, reports the sergeant with grim humor, was rude to Macdonwald because he "nev'r shook hands nor bade farewell to him" before he "unseamed him from the nave to th' chops" (split him open from his stomach to his throat). Then, just as Macbeth was routing the rebels, the Norwegian army staged a surprise attack that did not in the least frighten Macbeth and Banquo:
KING Dismayed not this / Our captains, Macbeth and Banquo?
CAPTAIN Yes; / As sparrow eagles, or the hare the lion. (1.2.32-35)
Undaunted, Macbeth and Banquo were like "cannons overcharged with double cracks," fearlessly exploding as does gunpowder, reports the sergeant; they quickly engaged the Norwegian army, leaving the battlefield like another Golgotha, a place of slaughter (also where Christ was crucified). With ferocity, Macbeth and Banquo overpower the enemy. However, the sergeant's wounds are so severe that he becomes faint and must go to the surgeon before finishing his report.
This scene holds much significance as the depiction of Macbeth as a fearless warrior and superior man establishes him as the material of a noble nature who can qualify as a tragic figure.
Here is a video that explains the different characters in Macbeth: