In Shakespeare's "Macbeth," the witches predict that Banquo will never be king but that his descendants will be kings. The witches also predict that Banquo will be happier than Macbeth.
In the beginning of the play, Macbeth and Banquo are allies. Macbeth has a strong desire to be king, and in his quest for power he sees Banquo as a threat; it is for this reason he has Banquo murdered. During a public feast, Banquo's ghost appears to Macbeth, which causes him to be scared. Banquo is often seen as the protagonist to Macbeth because he embraces all that is good, while Macbeth embraces evil.