Claudius
Claudius is the current king of Denmark. He's married to his dead brother's wife, Gertrude, which makes him Hamlet's uncle and stepfather. Claudius becomes the object of Hamlet's quest for revenge when the young prince learns that Claudius murdered his father.
Claudius and Biblical Allusion
How did Claudius murder his brother? By pouring poison in Old King Hamlet's ear while he was sleeping peacefully in his garden. The story sounds familiar, right? Claudius is on more than one occasion aligned with Cain, the biblical figure known for committing the first murder when he slew his brother, Abel, in the book of Genesis. Even Claudius admits his "offence is rank [and] smells to heaven [because] / It hath the primal eldest curse upon't, / A brother's murder (3.3.3). Claudius, then, is a central figure in the play's concern with the theme of "Family" relationships.
Claudius's murderous deed in the garden also recalls the biblical story of the fall. The Ghost (of Old Hamlet) says "[t]he serpent that did sting [Hamlet's] father's life / Now wears his crown. (1.5.8) The Ghost also goes on to say "that that incestuous, that adulterate beast, / With witchcraft of his wit, with traitorous gifts […] won to his shameful lust / The will of [Old Hamlet's] most seeming-virtuous queen (1.5.9). Hmm. Sounds like the Ghost is comparing Claudius to the infamous serpent who seduced Eve in the Garden of Eden. (We talk more about gardens in "Symbols, Imagery, Allegory," so be sure to check that section out.)
Claudius and Kingship
Claudius is also notable for the way his character speaks to the play's ideas about monarchy and power. "A bad man, but a good king." That's one scholarly assessment of Claudius's character. There's no question that Claudius is a bad man: nice guys don't kill their brothers and steal their wives. At the same time, Claudius certainly seems like a competent ruler. The fact that he manages to assume his brother's crown so smoothly is a testament to his powers of persuasion. As he says himself, he had to convince the nobles of the court to accept his bizarrely-timed and probably sinful marriage to Gertrude.
Aside from crown-stealing and wife-stealing, Claudius goes on to diplomatically avoid war with Norway and keep the members of his court (minus Hamlet) under control. We should note that the trouble between Denmark and Norway began when Old King Hamlet accepted Old Norway's challenge to a duel in which the winner would walk away with some of the other ruler's lands. Of course, Old Hamlet won the duel, but his willingness to gamble away part of his kingdom suggests he wasn't exactly the terrific king his son remembers. In any case, Claudius cleans up the mess with Norway when his negotiations prevent Old Norway's son (Fortinbras) from attacking Denmark in order to retrieve Norway's lost territory.
Later in the play, Claudius's handling of Laertes's rebellion is especially impressive. Even at sword point, Claudius manages to calm the kid down and convince him that he is innocent of Polonius's death. His palace is invaded by Laertes's followers, and still Claudius comes out on top – and wearing his crown.
Claudius as Machiavellian Ruler
It's often noted that Claudius (like so many of Shakespeare's other kings – think of Richard III, among others) resembles a Machiavellian ruler. (Note: Niccolò Machiavelli wrote The Prince, a "how to" guide for princes on the maintenance of power.) Machiavelli's ideas were controversial but his book (published 1532) was popular in Shakespeare's day. According to Machiavelli's theory, being a successful ruler has nothing to do with being a nice person or doing the right thing. Instead, it's about being inventive, charismatic, willful, and manipulative.
So it seems that the same characteristics that make Claudius a bad man are those that make him a successful king. He has no qualms about manipulating people, and he is unapologetically selfish. Hypocrisy barely bothers Claudius: he pretends to be a loving stepfather to Hamlet even while sending him off to be killed. Claudius doesn't let his conscience get in the way of the job that needs to be done. He also lets Gertrude drink a goblet of wine he knows is poisoned – the wine, of course, is intended for the oh so troublesome Hamlet but he'd rather see his wife die than risk ruining his plans. He does manage a "Gertrude, do not drink," but opts out of the perhaps more effective, "Gertrude, do not drink, whatever you do, as the wine is poisoned because I'm secretly trying to kill your son, and even though I really would rather have him dead, I'm not willing to let you go down as a casualty of my despicable and unlawful scheming."
