To What Extent is Macbeth pushed into killing king Duncan? Numerous people and factors push Macbeth into killing the king. The main factors are:  Lady Macbeth  The Witches and Fate  King Duncan  Banquo  Himself (Macbeth) I start with probably the most influential character upon Macbeth, his wife, Lady Macbeth. Lady Macbeth believes what the witches have said and therefore believes that she will become the queen. ‘Have I thought good to deliver thee’ She obviously has a great am ....