He cheated on his wife.
He committed treason against King Duncan and Scotland.
He killed the Queen.
He refused to go into battle because he was a coward.
Banquo's sons will be kings.
Macbeth will be the Thane of Cawdor.
Macbeth will be King of Scotland.
Banquo will kill Macbeth.
Duncan is an unfair leader.
Duncan is old and senile and can't take care of the country anymore.
Macbeth wants to be King himself.
Duncan insulted Macbeth's manhood.
The Weird Sisters
Here's an interesting quiz for you.