Short answers, pulled from the story.
Macbeth was written by William Shakespeare and is estimated to have been first performed in 1606. It was first published in the First Folio of 1623, the only source for the text. It is Shakespeare's shortest tragedy.
A Scottish general named Macbeth receives a prophecy from three witches that he will become King of Scotland. Spurred by his wife, he murders King Duncan and takes the throne, then commits further murders out of guilt and paranoia. He and Lady Macbeth descend into insanity and death, and Macbeth is finally killed by Macduff.
Shakespeare drew his story from Holinshed's Chronicles of 1587, a history of England, Scotland, and Ireland. He combined two similar accounts, one about a man named Donwald and another about Macbeth, an eleventh-century Scottish king. The events in the play differ extensively from the history of the real Macbeth.
Actors avoid saying the name Macbeth inside a theatre because of a superstition that it brings bad luck, injury, or death to a production. They call it The Scottish Play, The Bard's Play, or Mr. and Mrs. M instead. The superstition's origins have been traced to a satirical article by the critic Max Beerbohm.
King James I was the patron of Shakespeare's acting company, and Macbeth contains the most allusions to James of all the plays Shakespeare wrote during his reign. Many scholars link the play to the Gunpowder Plot of 1605, citing the Porter's speech as an allusion to the Jesuit Henry Garnet, executed on the 3rd of May 1606. The parade of eight kings is read as a compliment to James, who believed himself descended from Banquo.
Macbeth is confronted by Macduff at Dunsinane after Birnam Wood appears to move toward the castle. Trusting the prophecy that no man of woman born can kill him, Macbeth is undone when Macduff reveals he was born by Caesarean section. Macbeth is killed offstage, and Macduff returns carrying his severed head.