Kingship: Divine Right vs Tyrannical Rule
What makes a legitimate king? Shakespeare explores this crucial question by contrasting Duncan's benevolent leadership with Macbeth's tyrannical rule, showing how illegitimate power corrupts everything it touches.
Duncan embodies the ideal of divine kingship - his promise to "plant thee and labour to make thee full of growing" shows a king who uses power to nurture his people. Even in death, he's remembered as "the gracious Duncan," emphasising his divine right and natural authority.
Macbeth's illegitimate rule is perfectly captured in the metaphor of "a giant's robe upon a dwarfish thief." The title of king is too grand and noble for someone as morally flawed as Macbeth, highlighting his inadequacy and dishonour. Unlike Duncan, "those he commands move only in command, nothing in love" - his subjects obey through fear, not respect.
Historical context: Shakespeare's description of Banquo's "royalty of nature," "valour," and "wisdom" would have pleased King James I, since the real Banquo was thought to be his ancestor - clever political writing!