Act 1, Scene 1: The three infamous witches of Macbeth make their first appearance as they make convoluted conversation with each other amidst terrifying thunder and lightning. The "weird" sisters agree to reconvene once "the battle's lost and won" upon "the heath." (Act 1, Scene 1, Lines 4 7) The details of this battle are unknown until the later scenes in this act of the play.
Act 1, Scene 2: King Duncan, his sons Malcolm and Donalbain and the nobleman Lennox meet with a bleeding captain who recounts the details of the aforementioned battle. Malcolm bids the captain, who valiantly fought in the battle, to tell the king the present state of affairs. He says that the rebel Macdonwald swarmed the battlefield with his men, who claimed nativity from far-off places like the Western Isles. Although fate seemed to be with Macdonwald, Macbeth boldly made his way to the "rebel," split him from the navel to the jaws and hung his head over the battlefield. King Duncan praises Macbeth's courage and encourages the captain to continue with his narration. He says that just when the turn of events seemed favorable for Scotland, the Norwegian lord began a fresh assault with more men and supplies. Macbeth and Banquo, undeterred from their mission, continued to fight with ardor.
At this point, the captain reels from weakness and the king orders surgeons to attend to him. Ross and Angus, Scottish noblemen, hasten into the courtroom with a wild look in their eyes. Ross tells King Duncan that the traitorous Thane of Cawdor assisted the King of Norway in the battle. The title "thane" indicates a Scottish nobleman. He also tells the king, however, that after much bloody fight the victory fell to Scotland. Duncan prepares to make peace with Sweno, Norway's king and asks for ten thousand dollars from him in return for the proper burial of his men. In addition, King Duncan orders the immediate execution of the Thane of Cawdor and asks that Ross greet Macbeth with the news that he will be the new Thane of Cawdor. Duncan says, "What he [former Thane of Cawdor] hath lost, Macbeth hath won." (Act 1, Scene 2, Line 66) Thus, the king has fulfilled part of the witches' prophecy-"when the battle's lost and won." Furthermore, the fact that Macbeth defies fate in fighting Macdonwald indicates his propensity to twist the present to alter a supposedly fixed future. It is this courage to play with fate that made Macbeth murder his countless victims based on the advice of the witches.