HORATIO Now, sir, young Fortinbras, Of unimprovèd mettle hot and full, Hath in the skirts of Norway here and there Shark'd up a list of lawless resolutes For food and diet to some enterprise That hath a stomach in 't; which is no other (As it doth well appear unto our state) But to recover of us, by strong hand And terms compulsatory, those foresaid lands So by his father lost. And this, I take it, Is the main motive of our preparations, The source of this our watch and the chief head Of this posthaste and rummage in the land. (1.1.107-119)
Horatio speculates that the Ghost's appearance, in full armor, on the castle battlements is related to Denmark's troubles with Norway. But he's wrong: Old Hamlet's Ghost actually returns to ask his own son to avenge his murder. It seems pretty clear that Shakespeare wants us to pay attention to father-son relationships in this play.
HAMLET A little month, or ere those shoes were old With which she followed my poor father's body, Like Niobe, all tears—why she, even she (O, God, a beast, that wants discourse of reason Would have mourned longer!), married with my uncle, My father's brother, but no more like my father Than I to Hercules. (1.2.151-158)
Here, Hamlet is so bummed about Gertrude that he can't even speak in complete sentences. Check out how he compares her to Niobe, who grieved so bitterly for her dead children that she turned to stone—almost as if he thinks it's his funeral Gertrude attended and his death that Gertrude failed to mourn long enough.
HAMLET She married. O, most wicked speed, to post With such dexterity to incestuous sheets! It is not, nor it cannot come to good. But break, my heart, for I must hold my tongue. (1.2.161-164)
Hamlet not only takes issue with his mother's quick remarriage after his father's death, he's also disgusted by the fact that Gertrude is guilty of "incest." (Some critics also speculate that Hamlet secretly wants to sleep with his mother, which you can read about in our "Character Analysis" of Hamlet.)
But first, it's time for a history snack. In Shakespeare's time, incest included marrying your in-laws, not just your blood relatives. So, Claudius' marriage to Gertrude is a pretty big deal —they've broken the church's laws of affinity.
And there's something more particular about the whole marrying-your-brother thing. Elizabeth I, the Queen of England at the time Hamlet was written, was the daughter of King Henry VIII and Anne of Boleyn (Henry's second wife). Henry divorced his first wife, Catherine of Aragon, on the grounds that she had originally been married to his (dead) older brother, Arthur. Henry asked the Catholic Church to grant a divorce on grounds that his marriage to Catherine was incestuous. By making such a big deal out of Gertrude's remarriage, Shakespeare might be doing his part to assure Queen Elizabeth that her mom's marriage was legitimate.
LAERTES […] but you must fear, His greatness weighed, his will is not his own, For he himself is subject to his birth. He may not, as unvalued persons do, Carve for himself; for on his choice depends The safety and health of this whole state. And therefore must his choice be circumscribed Unto the voice and yielding of that body Whereof he is the head. (1.3.19-27)
Laertes tells Ophelia that Hamlet can't marry who he wants to—he has to marry for the "safety" of the entire "state." And he's right. If you were rich and powerful in the 16th century, your marriage was an opportunity to forge strategic political, social, and economic alliances. In other words, Laertes insists that a marriage between Ophelia and Hamlet is impossible. Marrying for love? That was for the commoners.
LAERTES […] Then if he says he loves you, It fits your wisdom so far to believe it As he in his particular act and place May give his saying deed, which is no further Than the main voice of Denmark goes withal. Then weigh what loss your honor may sustain If with too credent ear you list his songs Or lose your heart or your chaste treasure open To his unmastered importunity. (1.3.27-36)
Here, Laertes tells Ophelia that, if she sleeps with Hamlet, she'll lose her honor. But this isn't a moral argument on the ethics of premarital sex. He's talking about the way Ophelia's chances for a future marriage could be compromised—which is literally a matter of life or death for a young woman.
POLONIUS […] I would not, in plain terms, from this time forth Have you so slander any moment leisure As to give words or talk with the Lord Hamlet. Look to 't, I charge you. Come your ways.
OPHELIA I shall obey, my lord. (1.3.141-145)
Ophelia isn't actually agreeing here; she's just acknowledging that she has to obey Polonius. Parents in this play (and in powerful families of the Early Modern period) weren't necessarily interested in helping their kids develop to their fullest potential, or whatever the helicopter parenting line is now; they saw their kids as pawns in the game of life.
Act II, Scene i
POLONIUS […] and there put on him What forgeries you please—marry, none so rank As may dishonor him, take heed of that, But, sir, such wanton, wild and usual slips As are companions noted and most known To youth and liberty. (2.1.21-26)
In a long tradition of helicopter parenting, Polonius spies on his kid while he's away at college. And he's not the only one. Claudius, Hamlet's step-father / uncle, also goes to great lengths to find out what Hamlet's up to and even tries to have him murdered. We know that Hamlet idealizes his own father, but we wonder —if Old Hamlet were still alive, would he be any better than Claudius and Polonius?
KING O, my offence is rank, it smells to heaven; It hath the primal eldest curse upon 't, A brother's murder. (3.3.40-42)
As King Claudius prays, he acknowledges that, by murdering his brother, Old Hamlet, he has brought upon himself the first ("primal") and oldest ("eldest") "curse," which is a reference to the biblical story of Cain, who committed the first murder when he killed his brother Abel (Genesis 4.10-12). Apparently, family feuds go way back. Way back.
LAERTES O, treble woe Fall ten times treble on that cursèd head, Whose wicked deed thy most ingenious sense Deprived thee of!—Hold off the earth awhile, Till I have caught her once more in mine arms. (5.1.258-262)
Here, Laertes leaps into Ophelia's grave so he can hold "her once more in [his] arms." Oh, and this happens right before he fights with Ophelia's ex-boyfriend about who loves Ophelia the most. Traces of incestuous desire? Uh, yeah.
QUEEN He's fat and scant of breath.— Here, Hamlet, take my napkin; rub thy brows. The queen carouses to thy fortune, Hamlet. [She lifts the cup.] HAMLET Good madam. KING Gertrude, do not drink. QUEEN I will, my lord; I pray you pardon me. [She drinks.] KING [aside] It is the poisoned cup. It is too late. HAMLET I dare not drink yet, madam—by and by. QUEEN Come, let me wipe thy face. (5.2.313-321)
After Gertrude drinks the poisoned wine that Claudius has prepared for Hamlet (does she know it's poisoned?), she tenderly wipes the sweat from her son's brow. This is a rather motherly thing to do, especially if she drinks the wine in order to save her son's life. After all of Hamlet's accusations that Gertrude is a selfish mother, Hamlet finally gets the thing that he seems to want the most —a doting mom who will pay more attention to her son than she does her husband. Aw. We love happy endings.