The Three Witches or Weird Sisters are characters in William Shakespeare's play Macbeth (c. 1603--1607). Their origin lies in Holinshed's Chronicles (1587), a history of England, Scotland and Ireland. Other possible sources influencing their creation aside from Shakespeare's own imagination include British folklore, contemporary treatises on witchcraft including King James I and VI's Daemonologie, Scandinavian legends of the Norns, and ancient classical myths concerning the Fates, the Greek myths of the Moirai and the Roman myths of the Parcae. Portions of Thomas Middleton's play The Witch were incorporated into Macbeth around 1618.
Shakespeare's witches are prophets who hail the general Macbeth early in the play with predictions of his rise as king. Upon committing regicide and taking the throne of Scotland, Macbeth hears the trio deliver ambiguous prophecies threatening his downfall. The witches' dark and contradictory natures, their "filthy" trappings and activities, as well as their intercourse with the supernatural all set an ominous tone for the play.
In the eighteenth century the witches were portrayed in a variety of ways by artists such as Henry Fuseli. Since then, their role has proven somewhat difficult for many directors to portray, due to the tendency to make their parts exaggerated or overly sensational. Some have adapted the original Macbeth into different cultures, as in Orson Welles's performance making the witches voodoo priestesses. Film adaptations have seen the witches transformed into characters familiar to the modern world, such as hippies on drugs or goth schoolgirls. Their influence reaches the literary realm as well in such works as The Third Witch and the Harry Potter series.
Come and Go, a short play written in 1965 by Samuel Beckett, recalls the Three Witches of Shakespeare's Macbeth. It features only three characters, all women, named Flo, Vi, and Ru. The opening line: "When did we three last meet?"  recalls the "When shall we three meet again?" of Macbeth: Act 1, Scene 1. The Third Witch, a 2001 novel written by Rebecca Reisert, tells the story of the play through the eyes of a young girl named Gilly, one of the witches. Gilly seeks Macbeth's death out of revenge for killing her father.
J. K. Rowling has cited the Three Witches in Shakespeare's Macbeth as an influence in her Harry Potter series. In an interview with The Leaky Cauldron and MuggleNet, when asked, "What if [ Voldemort ] never heard the prophecy?", she said, "It's the 'Macbeth' idea. I absolutely adore 'Macbeth.' It is possibly my favourite Shakespeare play. And that's the question isn't it? If Macbeth hadn't met the witches, would he have killed Duncan? Would any of it have happened? Is it fated or did he make it happen? I believe he made it happen." On her website, she referred to Macbeth again in discussing the prophecy: "the prophecy (like the one the witches make to Macbeth, if anyone has read the play of the same name) becomes the catalyst for a situation that would never have occurred if it had not been made." More playfully, Rowling also invented a musical band popular in the Wizarding world called The Weird Sisters that appears in passing in several books in the series as well as the film adaptation of Harry Potter and the Goblet of Fire. The third Harry Potter movie's soundtrack featured a song by John Williams called "Double Trouble", a reference to the witches' line, "Double double, toil and trouble". The lyrics of the song were adapted from the Three Witches' spell in the play.