1. Claudius is Hamlet's uncle and the King of Denmark.
2. He married Gertrude, Hamlet's mother, soon after the death of his brother, Hamlet's father.
Why does Hamlet dislike him so much?
1. Hamlet holds Claudius responsible for the death of his father, King Hamlet.
2. Claudius's hasty marriage to Gertrude and his ruthless power grab also contribute to Hamlet's resentment and disgust toward him.