Macbeth is a Shakespearian tragedy set in ancient Scotland. It centres around a Scottish nobleman, Macbeth, who falls prey to the desires of unchecked ambition. With his wife urging him on Macbeth embarks on a murderous rampage which sees him successfully take absolute power, but at the cost of both he and his wife's sanity and eventually their lives. Macbeth brings forth such themes as the dangers of unchecked ambition and disloyalty, the emptiness of exercising power without scruples and the consequences of succumbing to temptation.
"We still have judgment here, that we but teach Bloody instructions, which, being taught, return to plague th' inventor: this even-handed justice commends the ingredients of our poisoned chalice to our own lips" (Act 1 Scene 7 v. 9-12).
Shakespeare wrote the play at a time when people were deeply superstitious. They widely believed that bad events in the natural world (eg. storms) were tied to bad behaviour disturbing the spiritual world. In this respect three witches play a prominent part in the play as they tempt Macbeth into realising his ambition with mysterious prophecies and apparitions.