Orsino is the Duke of Illyria, lover first of Olivia and then of Viola. Orsino, like Olivia, presents a false view of love that must be corrected in the course of the play. Orsino is infatuated with Olivia, who has repeatedly rejected him, while Viola, who is disguised as Cesario, Orsino's page, loves the duke but cannot tell him so. Utterly involved in his self-image as a brooding, rejected lover, Orsino cannot accept the fact that his passion for Olivia is misplaced. Though he is a humorous figure, a parody of the melancholy lovers of conventional 16th-century romances, he also displays aspects of psychological disorder—as Feste observes, he is irrationally changeable, his 'mind is a very opal' (2.4.75)—and his wrong-headedness contributes to a sense that all is not well in Illyria. 

When we first see the duke, he demonstrates his amusingly distorted slant on reality. In his absurdly romantic pose, he demands music to satiate his lovesick soul, insists that a particular phrase be repeated, then immediately orders that the music be stopped, saying,' 'Tis not so sweet now as it was before' (1.1.8). He tellingly reverses the image of Olivia as the object of a hunt, making himself the hunted. By the end of the scene, Olivia has almost no importance herself; Orsino is totally absorbed in his own fantasies. But Orsino is not in love with himself; he is in love with love. In 1.4 Viola, as Cesario, vainly tries to induce a sensible attitude in the duke. He boasts of his 'unstaid and skittish' (2.4.18) behavior, which he associates with love. Feste amusingly sings him a dirge of a love song, 'Come away death' (2.4.51-66), but Orsino does not recognize the implicit critique of his exaggerated melancholy. 

The duke resembles such earlier Shakespearean lovers as Silvius in As You Like It and Valentine in The Two Gentlemen of Verona. As those figures are mocked by Rosalind and Speed respectively, so Orsino is taken to task, comically by Feste and ironically by Viola, but like his predecessors, Orsino is hardheaded and resistant. Only the course of events can make things right for him, for he does not even recognize that they are amiss.

At the play's climax, the disquieting side of Orsino's misplaced emotions erupts in threatened violence, as Olivia's continuing rejection precipitates a menacing demonstration of frustrated masculine dominance as he decides to kill Cesario in a romantic gesture combining love and death. Proposing to 'sacrifice the lamb that I do love, / To spite a raven's heart within a dove' (5.1.128-129), he inadvertently acknowledges his affection for Cesario. His blindness has kept him from recognizing this, but his instincts have nonetheless directed him truly, and once Viola's identity is revealed, Orsino is immediately ready to love her. 

Sebastian is the lover of Olivia and twin brother of Viola. Sebastian and Viola's virtually perfect resemblance to each other—a convention of romantic comedy—permits the traditional comic confusion of mistaken identities, but it also provides for two different presentations of love's restorative power. Sebastian resolves issues that his sister has raised, and his entrance stimulates the play's climax and helps both Olivia and Orsino to fulfill their potential. 

Much of Sebastian's tale is similar to his sister's:  both are shipwrecked and saved by helpful seamen—Antonio, in Sebastian's case—who direct them to the court of Illyria; both are pursued by Olivia; both are threatened with combat by Sir Andrew; and both are betrothed in the play's happy ending. These parallels heighten the effect of the comic confusions that ensue when Sebastian is mistaken for Cesario, the disguised Viola, and it also emphasizes the function Sebastian serves when the mistakes are cleared up in 5.1. While Viola's pose as Cesario has inspired love—hers for Orsino and Olivia's for Cesario—Sebastian's arrival is necessary for these passions to be properly directed. 

The correct relationship among the play's lovers-skewed at first by Viola's disguise and Orsino's misplaced passion for Olivia—begins to take shape when Sebastian meets Olivia, who believes him to be Cesario, in 4.1. He is naturally mystified by this ardent woman, but he recognizes the value other love, even knowing that it is based on some mistake, and he boldly plays along. In the same spirit, Sebastian immediately accepts Olivia's proposal of marriage in 4.3.  Sebastian's situation in Illyria differs from Viola's in one highly significant way: while Viola is disguised as a man, Sebastian's gender is unconfused and permits him a forthrightness not available to his sister. When Sir Andrew and Sir Toby oppose him, his response is squarely in the tradition of masculine assertiveness: he fights and drives them away, in both 4.1 and 5.1. His clear-cut sexual identity allows Sebastian to provide the missing elements in the lives of the other characters. He is the manly youth of Viola's disguise, and he is the lover whom Olivia thought she had found in the disguised Viola. He is the dominant male that Orsino should be but has lost sight of through his romantic affectations. He is also to become the aristocratic husband that Malvolio has inappropriately aspired to be. 

Antonio is friend of Sebastian. After rescuing Sebastian from a shipwreck, Antonio admires the young man so much that he wishes to become his servant. Sebastian rejects this offer, but Antonio follows him to the court of Duke Orsino of Illyria, although he has many enemies there. In 3.4 he mistakes Sebastian's twin sister, Viola, who is disguised as a man, for Sebastian; the episode adds to the play's comic complexities. Antonio's increasing distress—he believes that Sebastian has betrayed him when Viola doesn't acknowledge him, and he is arrested and threatened with death as an old foe of Orsino—contributes to the play's undertone of disquiet and potential violence. 

Sir Toby Belch is the uncle of Olivia. The self-indulgent Sir Toby drinks and roars through life, and, with Maria, Sir Andrew, and Fabian, he represents a jocular, festive spirit that triumphs over the cold and humorless rigidity of Olivia's steward, Malvolio, in the play's comic subplot. His position is boldly presented in his first speech, when he complains of Olivia's mourning for her deceased brother, saying, 'What a plague means my niece to take the death other brother thus? I am sure care's an enemy to life' (1.3.1-3). Sir Toby laughs and carouses mightily and counters Malvolio's insistence on order with the famous rebuke, 'Dost thou think because thou art virtuous, there shall be no more cakes and ale?' (2.3.114-115). Like another, greater drunken knight, Sir John Falstaff, Sir Toby enacts a variety of comic roles: he is Sir Andrew's mentor in debauchery and joins the jester, Feste, in mockery and jokes. He is a singer of songs and a fierce master of the dueling code. He makes repeated references to dances in 1.3.113-131, 2.3.58, and 5.1.198. 

However, Sir Toby has a darker side as well. His selfishness is very apparent. He exploits both his friend and his niece. He spends the foolish Sir Andrew's money while pretending to promote his mercenary marriage to Olivia, boasting that he has taken his dupe for 'some two thousand strong, or so' (3.2.52-53). His drunkenness turns belligerent and incoherent in 1.5.121-122, 129-130. His practical joking has a vicious edge: he forces two unwilling combatants to a duel in 3.4, and he also pushes Maria's plot against Malvolio to a new extreme, gloating, 'we'll have him  in a dark room and bound ... we may carry it thus for our pleasure' (3.4.136-138). This course is criticized in his own fear of reprimand in 4.2.70-74 and by the efforts of Olivia and Orsino to mitigate Malvolio's humiliation in 5.1. Moreover, Sir Toby's final departure is ugly: he curses Sir Andrew as 'an ass-head and a coxcomb and a knave, a thin-faced knave, a gull!'  (5.1.204-205) after his own scheme to humiliate his friend has resulted in both of them being beaten by Sebastian. 

Sir Andrew Aguecheek is a friend of Sir Toby. Sir Andrew carouses with his friend while they visit the home of Olivia, Sir Toby's rich young niece, whom Sir Andrew is courting. Sir Toby takes merciless advantage of Sir Andrew, but it is impossible to pity such a ridiculous figure. He fancies himself a wit, though he is a dolt; a ladies' man, though he is gaunt and repulsive, as his name suggests; and a fighter, though he proves a coward. 

Sir Andrew's inanity is well demonstrated when he tries to imitate Viola’s rhetoric, though he clearly has no idea of its meaning. He proudly recites, ' "Odours", "pregnant", and "vouchsafed": I'll get 'em all three all ready' (3.1.93). He is foolishly ignorant of ordinary references, as when he calls Jezebel a man in 2.5.41, and he mistakes FESTE'S drinking song—'a song of good life' (2.3.36-37)—for a hymn to virtue and rejects it, saying, 'I care not for good life' (2.3.39). When Sir Toby offers to marry Maria out of delight with her plan against Malvolio, Sir Andrew duplicates the offer, forgetting his alleged love for Olivia, and then he seconds the next several remarks made (2.5.183-208) in a delicious example of comic slavishness. 

Sir Andrew's combination of quarrelsomeness and cowardice—referred to by Maria in 1.3.30-33—typified the braggart, a character type dating to ancient Roman Drama. Traditional, too, is the comeuppance Sir Andrew receives when he assaults Sebastian and is pummeled in 4.1 and 5.1. When Sir Toby receives the same treatment, he lashes out at Sir Andrew calling him, accurately if not charitably, 'an ass-head anoka coxcomb and a knave, a thin-faced knave, a gull !"(5.1.204-205).  

However, Sir Andrew is sufficiently developed to have a few poignant and sympathetic moments. Rejected by Maria, he despondently (though comically) despairs, 'Methinks sometimes I have no more wit than a Christian ... I am a great eater of beef, and I believe that does harm to my wit' (1.3.82-85). When he wistfully remarks, 'I was adored once' (2.3.181), we suddenly see that he has a past, a remembered youth.  We may not need to know more, but we recognize his humanity. 

Malvolio is the mean-spirited steward to Olivia. Malvolio is the focus of the comic subplot, in which a group of characters led by Maria and Sir Toby conspire to embarrass him, with the result that he is incarcerated as a lunatic. This plot is clearly secondary to the main story of the lovers—Viola, Orsino, Sebastian, and Olivia—but Malvolio is such a strongly drawn character that the play sometimes seems to centre on him. In fact, several documents of the 17th century identify the play as 'Malvolio', and leading actors have always been pleased to take the role. In addition to embodying an ordinary comic villain—an obvious misfit who mistreats others and in the end is humiliated by a crude stratagem—Malvolio is also a humanly interesting victim, and he inspires sympathy as well as derision, thus contributing to Shakespeare's ironic undercutting of the conventional romantic comedy. 

Malvolio rejects humor and love in favor of a stern coldness and a consuming personal ambition.  His dislike of merriment and his rigorously sober dress and behavior justify his name, an approximation of the Italian for 'ill will'. (These features also resemble the typical 16th-century—and later—stereotype of the Puritan, but Shakespeare certainly did not consider Malvolio a Puritan, as is clear in 2.3.140-146.) Malvolio opposes the frivolity of Sir Toby, Sir Andrew, and Feste in 2.3, inspiring Sir Toby's famous riposte, 'Dost thou think because thou art virtuous, there shall be no more cakes and ale?' (2.3.114-115). Driven away by this assault on his dignity, the angry Malvolio gratuitously threatens Maria, thereby triggering the plot that brings him down. 

The steward behaves badly to Viola, who is disguised as a young man, when he brusquely delivers Olivia's ring to her in 2.2, and he is unnecessarily nasty to Feste in 1.5. His churlish behavior quite plainly foreshadows the comeuppance that he later receives. Even more repellent is the cold ambition of his entirely loveless courtship of Olivia, undertaken in accordance with the comical instructions of Maria's letter but contemplated by him in 2.5, before he finds this missive. His musings on the power and position he hopes to gain strongly illuminate his personality, as he solemnly and pompously contemplates punishing Sir Toby. These boldly unattractive features have inspired scholarly speculations that Shakespeare intended Malvolio as a satire on a particular living person; Thomas Posthumous Hoby; William Knollus; Ambrose Willoughby, but these hypotheses have never been convincingly established and they do not alter the character's function in the play. 

For all his noxious characteristics, Malvolio is not a serious threat in the manner of, say, Shylock; ultimately he is simply laughed off the stage. Nor does he grow or change in the course of the play; instead he is exposed for what he is by the actions of other characters. There is no question about his destiny; in a comedy such a hypocrite and would-be villain deserves his downfall, and this comes about in an entertaining manner.   

Nevertheless, Malvolio's imprisonment and humiliation seem excessive relative to his offence. The 'problem of Malvolio', as this imbalance has long been called, lends the sub-plot a viciousness that contributes to Shakespeare presentation of comedy's limitations. Feste's teasing of the imprisoned Malvolio in 4.2 is undeniably humorous, but even Sir Toby concedes that this continuing torment of their victim may be going too far, remarking 'I would we were well rid of this knavery' (4.2.69-70). Then, provoking the steward's angry final departure in 5.1, Feste mocks the steward even more mercilessly. We sympathize with Malvolio's anger, which seems justifiable, and with his ugly departure and its cry for revenge 'on the whole pack of you!' (5.1.377) Despite the play's happy ending, an aftertaste of bitter feeling remains. A 19th-century critic, Charles Lamb, went so far as to find 'tragic interest' in 'the catastrophe of this character'. Although Malvolio lacks the grandeur of a tragic hero, Lamb's comment raises an interesting moral question:  How is Malvolio's shabby treatment—or his unrepentant final response—to be reconciled with the happy ending? 

While poetic justice requires that Malvolio be brought down, for his rejection of love is insane in the play's scheme of things, Shakespeare softens his actual defeat in several ways. The victim's final cry for vengeance is neutralized by Fabian’s wish that the conspirators' 'sportful malice . . . may rather pluck on laughter than revenge' (5.1.364-365). Moreover, the two leading figures of Illyria offer the promise of reconciliation: Olivia, though amused at the plot against her humiliated steward, is sympathetic towards him, saying, 'Alas, poor fool, how have they baffled thee!' (5.1.368), and Orsino orders that someone follow him and 'entreat him to a peace' (5.1.379). 

Feste is the jester, or professional Fool, in the household of Olivia. Feste represents the play's spirit of festivity, which eventually triumphs over the steward Malvolio’s chilly ill humor. Outside the coils of the lovers' confusions, Feste can take an ironic view of them and their world.  He appears in a number of settings, the better to apply his vision to all. He frequents the courts of both Olivia and Duke Orsino, encounters both Viola and Sebastian, challenges the first appearance of Malvolio, and takes part in the revelry of Sir Toby and Sir Andrew. He also carries the comic subplot to its farthest extreme, disguising himself as a curate, Sir Topas, and pretending to exorcise the imprisoned Malvolio. As he himself observes, 'Foolery, sir, doth walk about the orb like the sun, it shines everywhere' (3.1.39-40). 

As an officially designated fool, it is Feste's duty to point out with jests and barbs the folly of those who are supposed to be wise. As Viola remarks when she meets Feste, 'This fellow is wise enough to play the fool, / . . . For folly that he wisely shows is fit; / But wise men, folly-fall'n, quite taint their wit' (3.1.61-69), and Olivia tells Malvolio, 'There is no slander in an allowed fool, though he do nothing but rail' (1.5.93-94). Feste wittily demonstrates that Olivia is foolish to mourn her brother's ascent to heaven, and her good humor is immediately restored. Although his jests are less effective against Orsino's foolish self-image as a romantic melancholic, they make the duke's mental disorder plain. Feste compares himself to Sir Andrew, saying, 'Better a witty fool than a foolish wit' (1.5.36), pointing out both Sir Andrew's limitations and his own role. He also cares for the drunken Sir Toby, observing bitingly, 'the fool shall look to the madman* (1.5.138-139). 

Finally, Feste's pretended exorcism of Malvolio casts light on the steward's character. Malvolio's humorless ambition and incapacity to love are metaphorically alluded to in Feste's diagnosis: 'I say there is no darkness but ignorance; in which thou are more puzzled than the Egyptians in their fog' (4.2.43-45). The subsequent comic dialogue deals obliquely with Malvolio's underlying deficiency—his lack of concern for anyone but himself. Feste declares that Malvolio will 'remain ... in darkness [until] thou shalt . . . fear to kill a woodcock lest thou dispossess the soul of thy grandam' (4.2.58-61). 

In Twelfth Night Shakespeare deliberately undercut the conventions of romantic comedy; one of his techniques was to establish what has long been called 'the problem of Malvolio'; the steward's discomfiture seems out of proportion to his offence, giving rise to an uncertain response in the audience/ which responds with both delight at Malvolio's comeuppance and sympathy for his victimization. Feste's final encounter with Malvolio, upon the steward's release, contributes to this ambiguity. Here, they cruelly uses Malvolio's own words against him and then observes that 'the whirligig of time brings in his revenges' (5.1.375-376); while 'whirligig' is funny, 'revenges' is not. 

Feste's songs are an important part of his role, illuminating different aspects of the play. In 2.3 he sings a love song for boisterous Sir Toby and Sir Andrew, and the audience shares the delight of the two knights, but the lyrics have a somewhat depressing tinge, for they advocate seizing love while one is young because 'what's to come is still unsure' (2.3.50). This observation is part of the play's disturbing undertone, as is Feste's next song, 'Come away death' (2.4.51-66), which is humorously suited to Orsino's affected sadness but is also strikingly melancholy in itself. 

Olivia is a wealthy mistress of an estate in Illryia, the lover of Cesario-who, although she does not know it. is Viola in disguise-and later the bride of Sebastian. Olivia is the object of Duke Orsino’s unrequited romantic fantasies. Like Orsino, she impedes the drama's triumph of love; she, too has a false view of herself that she must overcome. Olivia moves from one illusion to another beginning with a willful withdrawal into seclusion and denial of life and then falling headlong into a passion that is based on a mistake. Only the course of events, beginning with the appearance of Sebastian, can correct matters, for Olivia is never aware other errors. 

Mourning her late brother, Olivia adopts an exaggerated, irrational stance that is acutely described by Valentine: •. . . like a cloistress she will veiled walk, / And water once a day her chamber round /With eye-on-ending brine- (1.1.28-30). Ironically her withdrawal gives her something in common with her steward, Malvolio, who scorns pleasure and love. 

However, grief is counter to Olivia's true nature. In 1 5 the glee with which she responds to the jester Feste’s comical teasing reveals that she is ""suited to the ascetic pose she has adopted, and she has the common sense to see Malvolio for what he is, saying •O you are sick of self-love, Malvolio, and taste with a distempered appetite.- (1.5.89-90); She forgets her brother once she has been smitten with the charms of, Cesario, and her pent-up instinct for love plunges her into a most extracting frenzy-(5.1.279).However, her passion is misplaced, not only because a disguised woman is its object but also because she is excessively self-involved, using what she knows to be shameful cunning' (3.1.118) to win her beloved. She admits •There's something in me that reproves my fault: / But such a headstrong potent fault it is, / That it but mocks reproof (3 4.205-207). Olivia has gone from scorning love in the name of propriety to being possessed by love beyond the reach of conscience. 

Maria is a chambermaid to Olivia. With Sir Toby, Sir Andrew, and Fabian, Maria represents the spirit of fun that opposes the humorless severity of Olivia's steward, Malvolio, in the play's comic subplot. Of the group, Maria is much the smartest. She devises the plot to embarrass the steward, and she composes the remarkably clever forged letter to Malvolio—read aloud by the victim himself in 2.5.92-159—playing on his ambitions and his vanity to impel him to bring about his own downfall. Then in 4.2 she devises a capstone to the joke, disguising the jester Feste as a curate, Sir Topas, to visit and torment Malvolio, who has been locked up as a lunatic. 

Viola is the lover of Duke Orsino of Illyria and twin sister of Sebastian. Viola is at the centre of the play's confusions. Separated from Sebastian in a shipwreck, Viola finds herself in Illyria. Disguised as a young man, Cesario, she meets and falls in love with Orsino, but her adopted persona prevents her from expressing her love for him except through service as his page. Orsino wishes her to court Olivia for him, placing her in a strange and difficult position that becomes worse when Olivia falls in love with Cesario. Viola, alone among the characters, knows the truth of this situation. While she is like the other Illyrians in her susceptibility to passion, she alone can honestly assess it, saying simply, '0 time thou must untangle this, not I, / It is too hard a knot for me t'untie' (2.2.39-40). 

Viola's capacity for love is extreme: when Orsino hysterical over Olivia's continued rejection, proposes to kill Cesario in a grand gesture, she calmly acquiesces, saying to him, 'I ... to do you rest, a thousand deaths would die' (5.1.130-131). Such self-sacrificing devotion strikes some readers as Christlike, and along with the powers of restoration displayed by Sebastian at the play's climax, it has influenced a religious interpretation of the play by some scholars although an entirely secular reading is probably more appropriate to the comedy and Viola's personality Though extravagant, Viola's attitude towards love is much more wholesome than the posturing’s of Orsino and Olivia, and her effect on these characters is positive. Her spirit and candour arouse love in Olivia who has been withdrawing into grief-filled seclusion. Similarly, although Orsino is wrapped up in his self-image as a melancholy rejected lover, he responds unconsciously to Viola's devotion, conceiving a fondness for Cesario that he eventually transforms into husbandly affection for the sort of loving wife he truly needs Viola is the heroine of the play, performing the monumental task of liberating Olivia and Orsino from their misconceived selves and thus making the play's climax possible. 

In the meantime, her frank good humor keeps the audience aware of the potential realignment of the lovers. She is not afraid to make telling remarks to Olivia on her unmarried state, arguing that you do usurp yourself: for what is yours to bestow is not yours to reserve' (1.5.188-190), and she is unafraid to counter Orsino's dramatic and boastful insistence that male love is grander than female observing (while speaking as a man herself), 'We men may say more, swear more, but indeed / Our shows are more than will: for still we prove / Much in our vows, but little in our love' (2.4.117-119). She entertains herself and the audience with ironic remarks on her own disguised state, asserting to Olivia that 'what I am, and what I would, are as secret as maidenhead' (1.5.219) and, flatly, that 'I am not what I am' (3 1 143). Speaking as Cesario, she ironically tells Orsino that she loves someone 'of your complexion' and about your years, my lord' (2.4.26, 28), hiding the tact, which the audience knows, that the object other love is Orsino himself. 

However, there is also an aspect of Viola's position that contributes to Twelfth Night's disturbing undertone. She cannot openly express her love, for her disguise inhibits her, and she thus embodies a disorder in the world of romantic comedy, just as Orsino and Olivia do in their self-delusion, though less blatantly She herself laments, 'Disguise, I see thou art a wickedness (2.2.26). Also, her disguise raises questions of sexual ambiguity that can be psychologically unnerving. In Shakespeare's time, Viola would of course have been played by a boy making her situation both funnier and more troubling.  The spectacle of one woman, played by a boy, mistakenly responding sexually to another one, also played by a boy, makes implicit reference to both male and female homosexuality, as well as to heterosexual love, in a way that is comical but also suggestive of hidden depths of human sexuality. While the modern use of actresses tends to obscure this point, the complexity of the situation retains some of its powerful and upsetting strength.