King Claudius is the main antagonist of William Shakespeare's play Hamlet and its film adaptions. He is the King of Denmark, known to be the brother to King Hamlet, second husband to Queen Gertrude, and uncle to Prince Hamlet (the hero of the story).
Claudius first appeared discussing about the issues over Hamlet's depression and an imminent Norwegian invasion led by Prince Fortinbras (whose father King Fortinbras was slain in battle by King Hamlet). But it wasn't until the ghost of King Hamlet came to light and told Hamlet that Claudius killed him by pouring ear poison to marry Gertrude and claim the throne.
To ensure that no one's suspecting that he's planning to avenge his father's death by killing Claudius, Hamlet pretends to act crazy, but this leads Claudius to have two of Hamlet's closest friends Rosencrantz and Guildenstern to secretly spy on Hamlet. When Hamlet commissioned a play based on the events of King Hamlet's murder, Claudius (who was watching the scene) walks away from the room, providing proof of his guilt behind the murder of King Hamlet.
Taking refuge in a church, Claudius prays for forgiveness while Hamlet eavesdrops, planning to kill him from behind. However, Hamlet cannot bear himself to do it, unwilling to send his uncle to Heaven, so he takes out his rage toward Gertrude for marrying Claudius. However, this leads to the death of Claudius' adviser Polonius, who was accidentally stabbed by Hamlet while he was spying on him and Gertrude. Upon learning of Polonius' death, Claudius decides to banish Hamlet to England, and secretly plots to have him executed by the King of England.
However, this was foiled as Hamlet returned back to Denmark (thanks to some pirates who treated him with respect), having gotten Rosencrantz and Guildenstern to be sent to their execution in England as punishment for their treachery against him. Claudius then decides to take action by arranging a swordfight between Hamlet and Polonius' son Laertes, who is bent on avenging his father and his sister Ophelia, who previously committed suicide after being forsaken of her love for Hamlet. As part of the plan, Laertes tips his sword with poison while Claudius puts the same poison on a wine cup as a token of congratulation in case that fails. Around the same time, Prince Fortinbras arrives to lead an invasion against Denmark with his army, hoping to avenge his father by taking control of the Danish throne.
During the sword-fight between Hamlet and Laretes, Claudius watches as Laertes strikes Hamlet with the poisoned blade, and in the scuffle, they switched blades and Hamlet strikes Laertes with the same blade. However, things get out of hand when Gertrude accidentally drinks the poisoned wine and succumbs to her death, much to everyone's horror (including Claudius, who is now wracked with extreme remorse for this). Finally realizing that things have gone out of hand and that he has been used, a remorseful Laertes reconciles with Hamlet and reveals Claudius' plot. This motivates a furious Hamlet to kill Claudius by stabbing in the back with the poisoned blade and forcing him to drink the poisoned wine to avenge his parents' deaths.
Following Claudius' death, Hamlet and Laertes succumb to their deaths, and in his final words, Hamlet announces Prince Fortinbras as the new successor to the throne. Upon arriving with his forces and learning about the events from Hamlet's friend Horatio, Prince Fortinbras (declaring himself the new King) orders for Hamlet to be buried with full honors.
- Claudius has been portrayed on film by Basil Sydney (1948), Alan Bates (1990), Derek Jacobi (1996), and Kyle McLaughlin (2000).
- Claudius is the inspiration for Scar in The Lion King; Both are brothers to a king and uncles of the main character, succeed in killing their brothers in order to take over, and try to kill their nephews, just to make sure they don't take over. However, unlike Claudius (who marries Gertrude to obtain the throne and expresses dear remorse for killing his brother), Scar doesn't marry his brother's wife Sarafi and holds no guilt over killing his brother.
- He is also the inspiration for Hades's Disney version. Both are brothers to a king and uncles of the main character and try to take over their home.