Lady Macbeth is an ambitious and powerful female character who lacks humanity. She calls upon evil spirits to deprive herself of her feminine caring instincts in order to convince Macbeth to murder King Duncan so that Macbeth can become king. Lady Macbeth's desire for power and kingship drives her mad with ambition for her husband. King Duncan is the initial king of Scotland, characterized by his formal, gracious language and expressions of humility.