How is Claudius ambitious in Hamlet?
Claudius's ambition motivates him to murder his brother, marry Queen Gertrude, and attempt to kill Hamlet. Claudius is depicted as a manipulative ambitious individual, who goes to great lengths to attain the title of king and preserve his position of power. Claudius unscrupulously poisons his defenseless brother and marries King Hamlet's wife shortly after committing regicide. Claudius then becomes worried about Prince Hamlet's erratic odd behavior and fears that he will threaten his position as king of Denmark. After spying on Prince Hamlet and discovering that he is responsible for Polonius's death, King Claudius attempts to have Hamlet murdered by sending him to England with Rosencrantz and Guildenstern. Upon Hamlet's surprising return, Claudius continues to reveal his ambitious nature and determination to secure his position as king by manipulating Laertes into fencing against Hamlet using a poison-tipped sword. Overall, Claudius's ambition and desire to protect his title as King of Denmark drive the plot of the play and affect the actions of the other characters.
For Claudius, ambition is everything. And Denmark is rotten because of it. A black cloud of moral degradation has been hanging over the realm ever since he murdered his way to the throne. Some people are ambitious for their family; others for their country. But for Claudius, ambition begins and ends with number one. As Claudius is such a selfish, driven man, everyone else must be subordinated to his overriding ambition. Inevitably, people get hurt in the process, trampled underfoot by by the demonic force of one man's insatiable ego. Indeed, most of the many deaths that occur during the play come about as a direct result of Claudius's ambition to expand and consolidate his power.
But ultimately, Claudius is undone by that ambition. Far from bringing order and stability to the realm, his unhappy reign has brought nothing but chaos and bloodshed. Fittingly, perhaps, he comes to be a victim of the very same tumult and instability that he's unleashed upon his kingdom.
Most of the events in “Hamlet” are triggered by Claudius’s ambition; when we first see him in Act 1, scene 2, his ambition seems to have brought him everything he ever wanted. By poisoning his brother and working his political connections, he secures the kingship for himself and wins the queen for himself (interesting thing to consider: was Gertrude in love with Claudius before the death of King Hamlet? The play doesn’t definitively answer). In Act 3, Claudius counts his ambition among the reasons he killed his brother: “My crown, mine own ambition, and my queen.” His ambition keeps him scheming late into the play: he expertly redirects Laertes’s anger at him onto Hamlet and concocts an elaborate plot to remove Hamlet for good. Ambition drives Claudius’s actions; in a sense, it drives the action of the play itself.
Claudius' ambition forms the heart of the entire play. Claudius is so ambitious, he is willing to kill his brother, the king, and take over his throne. He then marries his brother's wife to cement his hold on the throne. When this Hamlet begins to question Claudius and his actions, Claudius is willing to poison his own nephew/stepson. To protect his plan of poisoning Hamlet, he allows his wife to accidently drink the poison meant for Hamlet, resulting in her death. I'd say Claudius was pretty ambitious since he was willing to kill three members of his own family in order to be king of Denmark.