In Hamlet, by William Shakespeare, Hamlet is a young man who is mourning the death of his father, King Hamlet. Because Hamlet's mother, Gertrude, married Claudius so quickly, Hamlet suspects foul play in his father's death. His fears are confirmed by the ghost of his dead father, and in Act Three Hamlet confronts Gertrude with what he knows.
Hamlet is furious with her and does an effective job of contrasting his father with his uncle/stepfather, Claudius.
Look here, upon this picture, and on this,
The counterfeit presentment of two brothers.
See, what a grace was seated on this brow;
Hyperion's curls; the front of Jove himself;
An eye like Mars, to threaten and command;
A station like the herald Mercury
New-lighted on a heaven-kissing hill;
A combination and a form indeed,
Where every god did seem to set his seal,
To give the world assurance of a man:
This was your husband. Look you now, what follows:
Here is your husband; like a mildew'd ear,
Blasting his wholesome brother. Have you eyes?
Could you on this fair mountain leave to feed,
And batten on this moor?
One is the counterfeit of the other. King Hamlet was full of grace and authority, a man on whom "every god did set his seal." Hamlet compares his father to gods such as Jove, Mars, and Mercury. Claudius, on the other hand, is "like a mildew'd ear" compared to his brother." While King Hamlet was like a fair mountain, Claudius is like a foul-smelling, swampy moor. The evidence of the play supports what Hamlet says.
Since King Hamlet is dead when the play begins, we do not see many of his actions; however, we know he loved Gertrude and even after his death does not want Hamlet to punish her for whatever her role was in his death. This speaks of his great love for Gertrude as well as his understanding of Hamlet's temperament. We also know that King Hamlet was a wise king who was victorious in battle, as seen in his dealings with Old Fortinbras. In short, everything we know about King Hamlet shows him to be a good, decent, and noble man, worthy of his crown.
Claudius, on the other hand, murdered his own brother and married his brother's wife, thus usurping the throne for his own benefit. We know from their first scene together that Claudius does not understand Hamlet (nor does he care to); in fact, once he believes Hamlet suspects Claudius murdered King Hamlet, Claudius is perfectly willing to have Hamlet put to death. He is a conniving, duplicitous man who is willing to use Hamlet's own friends to ensure Hamlet's demise.
Claudius does seem to have a conscience, as evidenced from his confessional soliloquy in Act Three; however, his unwillingness to repent is stronger than his guilt. Claudius keeps many secrets from his wife, though he does seem genuinely grief-stricken when she accidentally drinks the poison he intended for her son.
King Hamlet, from everything we can discern, took care of his people and loved his wife and son. Claudius plots, schemes, and uses whoever and whatever he can to keep the throne he stole by murdering his own brother. It is not surprising, then, that Hamlet cannot keep himself from again scolding his mother about her poor trade in husbands.
Hamlet calls Claudius
A murderer and a villain;
A slave that is not twentieth part the tithe
Of your precedent lord; a vice of kings;
A cutpurse of the empire and the rule,
That from a shelf the precious diadem stole,
And put it in his pocket!
Despite his hyperbole and anger, Hamlet is right.