Macbeth's Murder of King Duncan Many factors were involved in Macbeth's decision to kill King Duncan. He had pressure from his wife, he had an idea in his head, given to him by the three witches, and he was extremely ambitious. All of these factors ultimately contributed to his death and his decision to kill his king. This whole situation is due to three witches who wanted to cause trouble for Macbeth. They knew from the beginning what would happen to him in the end. Macbeth is ambitious and the witches play on this by promising Macbeth great things, such as becoming King of Scotland and Thane of Cawdor. Immediately after speaking with the witches, it happens to be titled Thane of Cawdor. Macbeth now believes the witches' words and honestly believes that the crown of Scotland will fall to him by natural means. This idea goes awry when Duncan names Malcom his heir. Macbeth then, still believing in witches, continues with his plan to kill Duncan. Lady Macbeth is a very loving wife to Macbeth and wants to do everything she can for him to achieve his goals. It goes a little too far and puts too much pressure on Macbeth to commit crimes that he isn't sure he wants to commit. After Macbeth sends her a letter about the witches' premonitions, Lady Macbeth is no longer the sweet innocent woman we expect her to be. She turns into a person who is just as ambitious as her husband and wants to do whatever it takes to help him get Duncan out of the way. He even goes so far as to call Macbeth a coward and mock his courage when he fails to complete the job. She's even willing to do it herself (plant the bloody knife with the guard). Lady Macbeth constantly pressures Macbeth to do things he is unsure of. He almost turns into a bully who challenges Macbeth to go out and do evil things. In a soliloquy she even says that she wants to be freed from all her morals and values ​​so she can help him commit these crimes. Finally, we must look at the tragic flaw of the hero himself..