King Alonso of Naples is the father of Ferdinand. In 2.1, when Alonso and his followers are shipwrecked on the magician Prospero’s island, Alonso believes his son has drowned and his grief overwhelms him. In 3.3 Prospero's sprite Ariel, disguised as a Harpy, declares Alonso, Antonio, and Sebastian to be 'three men of sin' (3.3.53) and reminds the king that he helped Antonio depose Prospero as Duke of Milan (before the play began). Ariel cites the loss of Ferdinand as Alonso's punishment. The three are made insane by Prospero's magic and must be revived at the play's end, in 5.1. Faced with Prospero, Alonso willingly surrenders Milan to him and begs his pardon. When Prospero reveals the surviving Ferdinand, Alonso is overjoyed; his 'I say, Amen' (5.1.204) offers a religious reference that reinforces the play's point that providence can restore human happiness. 

Prospero is the magician-ruler of a remote island. Prospero, once the Duke of Milan, lives in exile with his daughter Miranda and two supernatural inhabitants of the island, Ariel and Caliban. Through magic, Prospero controls this world completely, and he is the central figure of the play, simultaneously the sparker and spectator of its various subplot. He has freed Ariel from a magic spell, in exchange for his service as an assistant; he also befriended Caliban at first but enslaved him after he attempted to rape Miranda. Though embittered by his exile, Prospero has gained wisdom through his sorcery, and when chance places his one-time enemies in his power, he uses his magic to create an atmosphere of reconciliation and forgiveness, providing for the future in the union of Miranda with Ferdinand, the son of his enemy. 

Having accomplished these things, Prospero sacrifices both his dominion over the island and his love of magic, choosing to return to Milan. In doing so, he restores a measure of justice to human society, for he had been unjustly deposed from authority before the play began. He also restores himself to a sound moral footing, for he had earlier placed a private concern—his study of magic—above his duty as a leader of society, with disastrous results. However, Prospero's success is not complete; he remains a melancholy figure at play's end, haunted by Caliban's enmity and his evil brother Antonio, who refuses regeneration. Thus Prospero brings out an important subtheme of The Tempest and of the Romances in general: that life is an admixture of good and evil and that good cannot completely eradicate bad. 

Prospero is a philosopher as well as a ruler. His magic is referred to as his 'Art' (1.2.1), consistently spelled with a capital A; this is a conventional allusion to Neoplatonic doctrines of the occult, familiar ideas in the 17th century. The Neoplatonic philosopher/magician attempted to elevate his soul through arcane knowledge of the divine, whether through alchemy, the reading of supernatural signs, or communication with spirits. If these efforts led to a magical manipulation of the real world, it was only as a byproduct of the search for spiritual knowledge. Prospero's original goal was to transcend nature, not control it. Nevertheless, it is clear that the pursuit of this goal was culpably selfish, for it resulted in his exile and the disruption of sound government in Milan, as he recounts in 1.2. He had insisted on studying magic rather "than governing and as a result had been deposed by Antonio. Conscious of his failing, regretful at leaving Ariel and the beauties of 'rough magic [and] heavenly music' (5.1. 50-52), distressed by his evident failure to educate Caliban, and, most important, frustrated by the intransigence of Antonio, Prospero returns to Milan at play's end without the satisfaction the conclusion brings to most of the other characters. Though restored to power, and though he has provided a hopeful future for others, he is a partial failure, and he knows it. 

Prospero is not a pleasant character. He is a distant and uncommunicative father and a tyrannical master.  His unjustified complaints that Miranda is not listening to him in 1.2 and his anguished disruption of the Masque in 4.1 are evidence of his temperamental nature. Only in his affection for Ariel is he a pleasant figure, but he is also capable of rounding vituperatively on the sprite —'Thou liest, malignant thing!' (1.2.257)—and threatening him—'I will . . . peg thee [to a tree] till / Thou hast howi'd away twelve winters' (1.2.294-296). His program of petty harassments of Caliban, recounted in 2.2.1-14, is equally repellent.

Prospero's exploitation of the island's inhabitants is a clearly established element of the play. Ariel, a free spirit by nature, is restive in his service, and Caliban even attempts a revolt. Some modern commentators go so far as to make this exploitation a central concern, and The Tempest has been presented as an allegory of colonialism and oppression. However, it is clear that Prospero's control has been employed for good, for he has undone the dominance of evil that he found on his arrival, when the villainous Caliban prevailed, and Ariel, a good spirit, was imprisoned by Caliban's mother. The inhumane treatment of Caliban and Ariel's dissatisfaction provide evidence of the inexorability of evil; good ends must often be compromised by morally unsatisfactory means.

A central theme of the play is transfiguration, as the characters undergo transformations that suggest the varying human capacity for improvement. Prospero's magic effects these alterations in the others, but he himself also undergoes a highly significant change.  His transformation occurs largely before the time of the play, but evidence of it remains. His decision that 'the rarer action is / In virtue than in vengeance' (5.1. 27-28) implies a temptation from which he refrains. We recognize that he has grown: first a scholar of magic, he became a seeker of revenge through super-natural means, but finally he has transcended magic altogether. Once he could say 'my library / Was dukedom large enough' (1.2.109-110), but at play's end he returns to Milan to resume his proper position as a leader of society. In so doing, he renounces his magical powers and discards his semi-devine status as the island's omnipotent ruler. Prospero accepts his humanity and comes to terms with the prospect of his own death, to which he will devote 'every third thought' (5.1.311). He leaves the future in the hands of Ferdinand and Miranda. 

Prospero's 'Art' fittingly takes the form of drama, the art practiced by Prospero's creator. Assisted by Ariel, Prospero produces three distinctly theatrical illusions—the Harpy’s banquet of 3,3, the betrothal masque of 4.1, and the presentation of Ferdinand and Miranda at chess in 5.1. As producer of these spectacles, Prospero comments on their nature at the close of the masque, in his famous speech beginning 'Our revels now are ended' (4.1.148). He points out the illusion involved and goes on to equate such an 'insubstantial pageant' (4.1.155) with life itself, which disappears once it is performed. 'We are such stuff / As dreams are made on', he concludes, 'and our little life / Is rounded with a sleep' (4.1.156-158). Many commentators have regarded Prospero's remarks as Shakespeare's personal valedictory to a career in the theatre. While this notion is imprecise, in that Shakespeare continued to write for the theatre after The Tempest, the passage does seem to reflect the experience of an artist whose long career has led to the belief that art's inherently illusory nature is analogous to, and probably related to, the impossibility of understanding life. Here we have a clue to the philosophy underlying a prominent feature of Shakespeare's work, his persistent attention to ambiguity. 

Antonio is the villainous brother of Prospero. Before the play begins, as we learn in 1.2, Antonio deposed Prospero as Duke of Milan with the help of King Alonzo of Naples. Fearful of Prospero's popularity, he staged a natural death for the duke, abandoning him and his daughter Miranda in a small boat at sea. In the play Antonio, along with Alonso and others, is shipwrecked on the island that Prospero rules in exile. He continues to display his villainy in large and small ways, derogating the optimism of Gonzalo and encouraging Alonso's brother Sebastian to assassinate the king and assume the throne of Naples. His manipulation of Sebastian in 2.1.197-285 is a striking demonstration of Machiavellian villainy, and for this Antonio has been compared to Shakespeare's great villains Richard III and Iago. 

Gonzalo Character in The Tempest, adviser to King Alonso of Naples. Gonzalo is a kind and charitable, if ineffectual, figure who is a foil to the cynical villainy of Antonio, Duke of Milan, his master's ally. Gonzalo's goodness is an important element in the play.  He persistently takes a generous and optimistic point of view, as in his fantasy of an ideal society in 2.1.143-164. At the play's close, when Prospero’s schemes result in a final reconciliation and the seemingly miraculous restoration of the king's son, Ferdinand, it is the ageing adviser—called by Prospero 'Holy Gonzalo, honourable man' (5.1.62)—who cries out, '0, rejoice / Beyond a common joy!' (5.1.206-207). 

Ferdinand is the lover of the magician Prospero’s daughter, Miranda. Prospero arranges the match between Miranda and the son of his old enemy, King Alonso of Naples, as part of the atmosphere of reconciliation and forgiveness with which he resolves his own exile. Prospero pretends to distrust Ferdinand and puts him to forced labor, but when the young man's love survives this trial, Prospero blesses the future marriage of the couple. Ferdinand's ardor is important to the play's scheme of things, for he and Miranda symbolize the healing value of love. Ferdinand is accordingly a sterotypical romantic leading man, though his role is relatively small. 

Stephano is the drunken butler of King Alonso of Naples, and the ally of Caliban in his plot to kill Prospero. Stephano is a loutish fellow who is drunk throughout his time on stage, bullies Caliban and Trinculo, and is ludicrously ineffective in carrying out the plot. In 3.2, when Stephano accepts Caliban's suggestion that after killing Prospero he take Miranda for himself, we see that a supposedly civilized man is capable of villainy as deep as that of a bestial savage (for Caliban had already attempted to rape the young woman). Stephano's bluff—and drunken—courage distinguishes him from his companions, but when he is comically distracted from the assassination by the trivial vanity of fancy clothes in 4.1, he seems inferior to even the sub-human Caliban, at least in discipline. He offers an interesting sidelight on one of the play's themes, the relative merits of civilized and natural humanity; in his drunken foolishness, Stephano demonstrates the potential for evil inherent in civilization's pleasures. 

Trinculo is a jester to King Alonso of Naples and a follower of Stephano and Caliban in their plot to kill Prospero. Trinculo is a buffoon, drunk most of the time, and alternately servile and presumptious. He is ridiculously terrified of the weather when he first appears in 2.2 and is a butt for humor when Stephano sides with Caliban against him in 3.2, especially when the invisible Ariel imitates his voice and makes him seem argumentative when he is in fact entirely docile. In 4.1 Trinculo is comically obsequious towards Stephano, in a parody of the relationship between courtier and king. When the trio of would-be assassins is finally punished, Trinculo can only observe ruefully, T have been in such a pickle . . . that, I fear me, will never out of my bones' (5 1 282-283). 

Caliban is the beastlike slave of the magician Prospero. Before the time of the play, Prospero and his daughter Miranda took Caliban, the illegitimate son of a witch and a devil, into their home and taught him to speak and function as a human, but his response was to attempt to rape the girl. In the course of the play he and Stephano attempt to murder Prospero. Though Caliban is powerless to effect his schemes, his villainous nature is an important element in The Tempest's scheme of things. At the play's close a chastened Caliban declares, 'I'll be wise hereafter, / And seek for grace' (5.1.294-295) as part of the general reconciliation engineered by Prospero.  Caliban is only partly human. He is a 'monster' (2.2.66), a 'moon-calf (2.2.107), a 'born devil' (4.1. 188), and a 'thing of darkness' (5.1.275). Because his father was a devil, Caliban is supernatural like Ariel, but unlike that airy spirit, he has no supernatural powers. He is more like a debased human than like any other supernatural creature in Shakespeare. He has intelligence enough to learn language, but he is seemingly incapable of moral sense; reminded of his attempted rape, he merely asserts his animal drive to procreate. Caliban serves as a foil for the other characters: his foolish credulity in accepting Stephano as a god contrasts with Prospero's wisdom, his viciousness with Miranda's innocence, his amorality with the honorable love of Ferdinand, and, most significantly, his finally regenerate state with the intransigent evil of Antonio. 

Caliban's human qualities illuminate another of the play's themes and, in doing so, shed light on Shakespeare's world, which was just becoming aware of the natives of America. As Prospero's 'slave' (1.2.310) Caliban is linked with America; his mother's god, Setebos, was known by Shakespeare as a South American deity; in finding Stephano divine and in responding greedily to his liquor, Caliban behaves like the American natives of early explorers' accounts. 

The discovery of native American societies in the early 17th century stimulated debate on an ancient question: is 'natural man' a savage whose life is governed only by animal drives, or is he in a blessed state, unspoiled by the manifold corruptions of civilisation? Although the idealism of the latter view is reflected in Gonzalo’s praise of primitive society in 2.1.143-164 (drawn from remarks on America by the French essayist Montaigne), Caliban's nature contradicts it. He represents 'natural man', but his very name, an anagram of'canibal' (a legitimate 17th-century spelling of 'cannibal'), lends a negative quality to the connection. It is precisely his naturalness that condemns Caliban. He is confined to brute slavery because he has refused to accept a civil role in Prospero's household.  Prospero says that 'on [his] nature / Nurture can never stick' (4.1.188-189). In a telling comparison, Caliban's resistance to his wood-carrying chores is contrasted with Ferdinand's philosophical delight in similar labors. The young man knows that 'some kinds of baseness / Are nobly undergone; and most poor matters / Point to rich ends' (3.1.2-4). Miranda expressly judges both Ferdinand and Caliban: the first is 'a thing divine' (4.1.421), the second, 'a thing most brutish' (1.2.358). 

Yet Caliban has some positive attributes, which qualify Shakespeare's condemnation of'natural man'. Though he proclaims that his education has merely taught him 'how to curse' (1.2.366), his use of language is in fact quite impressive, and he rises to lyrical poetry—revealing an aesthetic sensibility—in describing his dreams of 'a thousand (wangling instruments' (3.2.135). He can imagine a level below himself to which he does not want to descend, for he fears he and his companions will be 'turn'd to barnacles, or to apes / With foreheads villainous low' (4.1.248-249). Though he is foolish enough to follow Stephano and Trinculo, he is more sensible than they and scorns their frivolous absorption with mere 'luggage' (4.1. 231). His proposed revolt is both repulsive and ineffectual, but Caliban's dislike for his enslavement is one with which we instinctively sympathize. His initial statement of grievance is compelling; he helped Prospero and Miranda survive and is now enslaved. Only then do we learn of his crime, but even afterwards, Caliban is permitted his say on his status: his elaborate complaint of Prospero's harassment in 2.2.1-14 casts his master in a bad light, and his comical enthusiasm for 'Freedom, high-day! high-day, freedom! freedom, high-day, freedom!' (2.2.186-187) is infectious. 

Miranda is the daughter of the magician Prospero. Miranda, exiled with her father at the age of two, has lived 12 years with him on the island he rules through sorcery. It is uninhabited except for the supernatural creatures Ariel and Caliban, so when Prospero's magic brings people to the island, Miranda sees her first young man, Ferdinand, with whom she falls in love—and he with her—in 1.2. Prospero has planned this—Ferdinand is the son of his old enemy. King Alonso of Naples—but he pretends to oppose the couple's love to ensure that Ferdinand does not take Miranda lightly. Prospero takes the young man captive, but Miranda contrives to visit him, and they confess their love and plan to marry in 3.1; in 4.1 Prospero declares his approval. As part of Prospero's arrangements for a conclusion of forgiveness and happiness, in 5.1 Miranda and Ferdinand are revealed to King Alonso, who believed his son had drowned. Miranda's marriage plans are confirmed, and Alonso declares that she and Ferdinand will inherit the kingdom of Naples. 

Miranda does not speak often or at length, but she is established as a paragon of maidenhood. She displays a touching compassion—fearing for the shipwreck victims, she says, '0, I have suffered / With those that I saw suffer!' (1.2.5-6). She also shows a capacity for delighted wonder; on first seeing Ferdinand, she cries, 'I might call him / A thing divine; for nothing natural / I ever saw so noble' (1.2.420-422). Her angry disdain for Caliban, who once attempted to rape her, displays the moral sensibility she has learned from her father, but her innocence of society gives her a simplicity that in a less overtly fantastic context would be disconcerting. She ignores the fact that Ferdinand is the son of her father's enemy, and at the play's close she is filled with pleased admiration for all of the king's party, even though some of them are arrant villains, saying, 'How beauteous mankind is! O brave new world, / That has such people in 't!' (5.1. 183-184). 

Miranda represents the compassionate, forgiving, and optimistic potential in humanity. She is the only human character in the play who does not undergo some sort of purging transformation, for she does not need to. Innocent of life's difficulties and compromises, she repudiates evil and responds to nobility and beauty. She is most pointedly contrasted with the evil Caliban. Both were raised together by Prospero, but she has become a person of moral sensibility, while he is a would-be rapist who declares that his only use for language is to curse. Their responses to the arrival of strangers on the island are also contrasting: she is filled with demure awe, he with crass fear. 

Though innocent, Miranda is nonetheless mindful of sexual propriety, speaking of her 'modesty, the jewel in [her] dower' (3.1.53-54) and declaring that if Ferdinand will not marry her, she will 'die [his] maid' (3.1.84). Her virginity—stressed repeatedly by the men, as in Ferdinand's first declaration of love and in Prospero's emphatic concern about sex before marriage—link her to an ancient archetype, the fertile woman, producer of new generations. The goddesses at her betrothal Masque sing of 'Earth's increase' and 'plants with goodly burthen bowing' (4.1.110, 113), making it clear that the occasion concerns reproduction. They also stress Miranda's virginity, for a sure knowledge of paternity has traditionally been very important to the orderly continuation of society. This is especially true among rulers, and Miranda's future as a queen is frequently pointed up. At the play's close, after Prospero's reconciliations have been effected, Gonzalo blesses the moment and delights in the prospect that Prospero's 'issue / Should become Kings of Naples' (5.1.205-206). Miranda thus helps fulfill that most ancient of necessities for human societies, continuance into the future. She and Ferdinand embody the regeneration that is the theme of the play's close. 

Ariel is a sprite or fairy, who serves the magician Prospero.  Ariel is invisible to all but Prospero, whom he assists in the schemes that form the plot. He is capable of assuming fantastic disguises and of luring mortals with supernaturally compelling music. He is also something of a theatrical producer, arranging the spectacular tableaus that Prospero is fond of, including the magical banquet of 3.3 and the betrothal Masque of 4.1. He performs in both, playing a Harpy at the feast and either Ceres or Iris (depending on one's reading of 4.1.167) in the masque. Ariel is eager to please, asking, 'What shall I do? say what; what shall I do?' (1.2.300). To his question 'Do you love me, master?' (4.1.48), Prospero replies, 'Dearly, my delicate Ariel' (4.1.49), and when Prospero returns to MILAN and resumes his role in human society, he regrets departing from the sprite, saying 'my dainty Ariel! I shall miss thee' (5.1.95). A cheerful and intelligent being, Ariel embodies the power of good and is thus an appropriate helper in Prospero's effort to combat the evil represented by Antonio. In this respect he contrasts strongly with the play's other major non-human figure, Caliban, whose innate evil complicates Prospero's task. 

Iris is a Pagan goddess and minor figure in The Tempest, a character in the Masque presented by the sprite Ariel to celebrate the engagement of Miranda and Ferdinand. Iris—goddess of the rainbow and messenger of the greater deities—functions as the 'presenter' of the masque, which features Ceres, goddess of harvests; Juno, queen of the gods; and a dance of Nymphs and Reapers. Iris' beautiful invocation to Ceres in 4.1.60-75 establishes a tone of serene power appropriate to divinity. Ariel subsequently declares that he 'presented Ceres' (4.1.167), indicating that he played the part of either Ceres or Iris, the presenter; most commentators believe Shakespeare intended the former, with Iris' initial speech providing time for Ariel to costume himself. 

Ceres is a Pagan goddess and a character in the Masque presented by the sprite Ariel, at Prospero’s orders, to celebrate the engagement of Miranda and Ferdinand. Ceres, goddess of harvests, is presented by IRIS but declares she will not participate unless she can be assured that Venus and Cupid will not be present. This reminds us of Prospero's insistence on Miranda's virginity before marriage, part of the play's theme of moral discipline.  Once reassured, Ceres joins Juno in singing a hymn of blessing, wishing 'Earth's increase, foison [abundance] plenty' (4.1.110) for the couple.