Hamlet’s major antagonist is a shrewd, lustful, conniving king who contrasts sharply with the other male characters in the play. Whereas most of the other important men in Hamlet are preoccupied with ideas of justice, revenge, and moral balance, Claudius is bent upon maintaining his own power. The old King Hamlet was a stern warrior, but Claudius, his brother, is a corrupt politician whose main weapon is his ability to manipulate others through a skillful use of language. When it comes to international diplomacy, this influence actually works in Denmark’s favor. After all, Claudius is the one who manages to convince the king of Norway to intervene in Fortinbras’s planned invasion of Denmark. Within the royal court, however, his speech is like the literal poison that he pours in Old Hamlet’s ear. Claudius has the ability to convince others to follow his commands regardless of how morally questionable they may be. Through his charisma and persuasive attitude, he gets Gertrude to marry him, invites Rosencrantz and Guildenstern to spy on Hamlet, and turns Laertes into his ally. 

While Claudius may outwardly present himself as a strong and unwavering leader, he begins to crumble internally as the play progresses. His mounting fear of Hamlet’s insanity exacerbates his self-preservation instincts, and the weight of his evil deeds begin to take a toll on his conscience. Moments such as Claudius’s abrupt departure from the Players’ performance and his “O, my offence is rank” soliloquy suggest that he is capable of feeling guilt, and by including this detail, Shakespeare reminds the audience that he is a complex individual rather than a stock character. Unfortunately, Claudius’s sense of guilt is not strong enough to assuage his desire for power. When Gertrude reveals that Hamlet has killed Polonius, for example, Claudius only expresses concern for his personal safety and fails to acknowledge that his wife had been in danger. His need to ensure the continuation of his rule above all else ultimately leads to his demise. In Act 5, Scene 2, Claudius insists that, in addition to Laertes’s sharpened sword and the poison on the blade, a poisoned goblet must be present to guarantee that Hamlet dies. Ironically, the goblet, a symbol of Claudius’s unchecked greed and desperation, is the thing that kills both Gertrude and himself. His own cowardly machination inevitably destroys him.