The witches, or "weird sisters," as they are often called, play a pivotal role in Macbeth. Macbeth himself is obsessed with their prophecies, and repeatedly consults with them. After discovering the prophecy, he then makes the decision to kill Duncan. This is the beginning of the downfall of his character. Soon after, to fulfill the prophecy he orders the death of his friend Banquo and son. This brings about the hallucinations and insanity. Thanks to the witches he believes he is immortal. We know very little about the true identity of the witches; however, their role is clear, they are Fate. The witches weave their way into Macbeth's life clearly to change destiny and toy with his future and destroy humanity. Without the witches, Macbeth would not have started on the dark path of murder and despair.