To What Extent is Macbeth pushed into killing king Duncan? Numerous people and factors push Macbeth into killing the king. The main factors are:  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 ambition and will do almost anything to fulfil her ambition. This shows a great evilness in her ‘