The Three Witches gave Macbeth and Banquo three prophecies each. Macbeth would be Thane of Glamis, Thane of Cawdor, and King HEreafter
During the battle that Macbeth fought in, the old Thane of Cawdor betrayed their country. King Duncan then made Macbeth the new Thane. The Witch's prophecies were coming true! Macbeth had to write to his wife! When Lady Macbeth read the letter her mind automatically went to the thought of becoming Queen. She devised a plan to kill the king!
King Duncan wanted to celebrate after the battle. He suggested a party at the Macbeth castle Inverness. Lady Macbeth was set on her plan to kill the king, but Macbeth felt guilty. She convinced him that it would make him king and it would be worth it.
The plan was set. They would wait until Duncan was asleep. They would get his chamberlains drunk then use their weapons to kill the king. Afterward they would wipe the blood on the chamberlains.
That night at Inverness Macbeth and Lady Macbeth were ready to fulfill their plan.
Macbeth has killed Duncan!
Macbeth forgot to put the knives by the chamberlains and wipe blood on them. Lady Macbeth was angry and decided it would be better if she did it instead.