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 apparently a stern warrior, but Claudius is a corrupt politician whose main weapon is his ability to manipulate others through his skillful use of language. Claudius’s speech is compared to poison being poured in the ear—the method he used to murder Hamlet’s father. Claudius’s love for Gertrude may be sincere, but it also seems likely that he married her as a strategic move, to help him win the throne away from Hamlet after the death of the king.
As the play progresses, Claudius’s mounting fear of Hamlet’s insanity leads him to ever greater self-preoccupation; when Gertrude tells him that Hamlet has killed Polonius, Claudius does not remark that Gertrude might have been in danger, but only that he would have been in danger had he been in the room. He tells Laertes the same thing as he attempts to soothe the young man’s anger after his father’s death. Claudius is ultimately too crafty for his own good. In Act V, scene ii, rather than allowing Laertes only two methods of killing Hamlet, the sharpened sword and the poison on the blade, Claudius insists on a third, the poisoned goblet. When Gertrude inadvertently drinks the poison and dies, Hamlet is at last able to bring himself to kill Claudius, and the king is felled by his own cowardly machination.
Claudius does manage to be sensitive and gentle. He is genuinely sorry for Polonius’ death, and he truly loves Gertrude. He must kill Hamlet, but he refuses to do so with his own hand for Gertrude’s sake. He also sincerely likes Ophelia, and treats her with the kindness that she should receive from her great love, Hamlet. But even those whom Claudius cares for cannot come before his ambition and desires. He will use the grieving Laertes to whatever ends necessary, and he denies Rozencrantz and Guildenstern the knowledge of the contents of the letter to England — knowledge that would have saved their lives, or at least made them proceed with caution. And Claudius does not stop Gertrude from drinking the poison in the goblet during the duel between Hamlet and Laertes because it will implicate him in the plot.
“The king doth wake tonight and takes his rouse,
Keeps wassail, and the swaggering up-spring reels;
And as he drains his draughts of Renish down,
The kettle-drum and trumpet thus bray out
The triumph of his pledge”
“O, ’tis true!
How smart a lash that speech doth give my conscience!
The harlot’s cheek, beautied with plastering art,
Is not more ugly to the thing that helps it
Than is my deed to my most painted word:
O heavy burden!”
“My fault is past. But O, what form of prayer
Can serve my turn? Forgive me my foul murder?
That cannot be, since I am still possess’d
Of those effects for which I did the murder,
My crown, mine own ambition, and my queen.”