When Macbeth learns that the current Thane of Cawdor has been executed for treason, he sees this as an opportunity to seize power. He murders Duncan, the rightful king of Scotland, and takes the throne for himself. However, Macbeth is plagued by guilt and paranoia after the murder, and he begins to spiral out of control.
The title of Thane of Cawdor is a symbol of Macbeth's ambition and greed, and it ultimately leads to his downfall. Macbeth ultimately meets a tragic end as he becomes increasingly isolated and paranoid, driven to madness by his guilt and the realization that the witches' prophecies have brought him nothing but sorrow and destruction.