Answer:
Macbeth is a tragic play that was written by William Shakespeare and which was first presented to the public in 1606. This story narrates the life and events of Macbeth and his wife, who, spurred into limitless ambition due to the prophecies given to Macbeth on the part of three witches, take actions that later on come to make them regret what they have done; kill the king, murder friends, murder enemies in cold blood, and rule a kingdom that was not theirs, with a tyrannical hand. Their actions come to pay them back in the end.
Probably one of the most vital events of the play, is the first time that the Weird Sisters, also known as the Three Witches, meet with Macbeth. On that first ocassion, they meet with both Macbeth and Baquo, just as they have been successful in the campaign of their current King, Duncan. The sisters tell each of the men what will happen to them in the future, and although reticent at first, things come to happen as were told, and Macbeth believes. He then acts, also pushed by his wife, as it appears in Act I, and II, to kill the king and assume the throne. If this event had changed, if the Sisters had not accurately told Macbeth that he was going to be named Thane of Cawdor, thus giving credit to their prediction that he would become king of Scotland, then Macbeth would have never gotten himself involved in so much corruption and decadence. Neither would he have pulled his own wife into that funnel of limitless greed that caused their ends. Another thing that would have changed is that the prediction for Banquo would have not come to pass. Because of Macbeth´s memory of what the Sisters told his friend, he is forced to have his friend murdered, and this, in turn, releases a series of events that make all the prophecies be fulfilled: Macbeth gets the throne, but he suffers from the guilt, he loses himself, and in the end, he loses his life and Banquo´s descendants take over the throne.