The Macbeth Quintet is a group of five characters from William Shakespeare's tragedy Macbeth. The group consists of Macbeth, his wife Lady Macbeth, the three witches, and Banquo. The term 'Macbeth Quintet' is derived from the fact that these five characters are the most important characters in the play. They are responsible for the events that unfold throughout the story and ultimately lead to Macbeth's downfall.