Othello has been one of Shakespeare's most popular plays, both among playgoers and literary critics, since its first performance, spawning numerous stage, screen, and operatic adaptations. Among actors, the roles of Othello, Iago, Desdemona, and sometimes Emilia (Iago's wife) are regarded as highly demanding and desirable. Critical attention has focused on the nature of the play's tragedy, its unusual mechanics, its treatment of race, and on the motivations of Iago and his relationship to Othello. Originally performed by white actors in dark makeup, the role of Othello began to be played by black actors beginning in the 19th century.
Shakespeare's major source for the play was a novella by Cinthio, the plot of which Shakespeare borrowed and reworked substantially. Though not among Shakespeare's longest plays, it contains two of his four longest roles in Othello and Iago.
Roderigo, a wealthy and dissolute gentleman, complains to his friend Iago, an ensign, that Iago has not told him about the recent secret marriage between Desdemona, the daughter of Brabantio, a senator, and Othello, a Moorish general in the Venetian army. Roderigo is upset because he loves Desdemona and had asked her father, Brabantio, for her hand in marriage, which Brabantio denied him.
Iago hates Othello for promoting an aristocrat named Cassio above him, whom Iago considers a less capable soldier than himself. Iago tells Roderigo that he plans to exploit Othello for his own advantage and convinces Roderigo to wake Brabantio and tell him about his daughter's elopement. Meanwhile, Iago sneaks away to find Othello and warns him that Brabantio is coming for him.
Brabantio, provoked by Roderigo, is enraged and seeks to confront Othello, but he finds Othello accompanied by the Duke of Venice's guards, who prevent violence. News has arrived in Venice that the Turks are going to attack Cyprus, and Othello is therefore summoned to advise the senators. Brabantio has no option but to accompany Othello to the Duke's residence, where he accuses Othello of seducing Desdemona by witchcraft.
Othello defends himself before the Duke of Venice, Brabantio's kinsmen Lodovico and Gratiano, and various senators. Othello explains that, while he was invited to Brabantio's home, Desdemona became enamoured of him for the sad and compelling stories he told of his life before Venice, not because of any witchcraft. The senate is satisfied once Desdemona confirms that she loves Othello, but Brabantio leaves, saying that Desdemona will betray Othello: "Look to her, Moor, if thou hast eyes to see. She has deceived her father, and may thee" (Act I, Sc 3). Iago, still in the room, takes note of Brabantio's remark. By order of the Duke, Othello leaves Venice to command the Venetian armies against invading Turks on the island of Cyprus, accompanied by his new wife, his new lieutenant Cassio, his ensign Iago, and Iago's wife, Emilia, as Desdemona's attendant.
The party arrives in Cyprus to find that a storm has destroyed the Turkish fleet. Othello orders a general celebration and leaves to consummate his marriage with Desdemona. In his absence, Iago gets Cassio drunk, and then persuades Roderigo to draw Cassio into a fight. Montano tries to calm down an angry and drunk Cassio. This leads to their fighting one another and Montano's being injured. Othello arrives and questions the men as to what happened. Othello blames Cassio for the disturbance and strips him of his rank. Cassio, distraught, is then persuaded by Iago to ask Desdemona to persuade her husband to reinstate him.
Iago persuades Othello to be suspicious of Cassio and Desdemona's relationship. When Desdemona drops a handkerchief (the first gift given to her by Othello), Emilia finds it and gives it to Iago at his request, unaware of what he plans to do with it. Othello appears and, then being convinced by Iago of his wife's unfaithfulness with his captain, vows with Iago for the death of Desdemona and Cassio, after which he makes Iago his lieutenant.
Iago plants the handkerchief in Cassio's lodgings, then tells Othello to watch Cassio's reactions while Iago questions him. Iago goads Cassio on to talk about his affair with Bianca, a local courtesan, but whispers her name so quietly that Othello believes the two men are talking about Desdemona. Later, Bianca accuses Cassio of giving her a second-hand gift which he had received from another lover. Othello sees this, and Iago convinces him that Cassio received the handkerchief from Desdemona.
Enraged and hurt, Othello resolves to kill his wife and tells Iago to kill Cassio. Othello proceeds to make Desdemona's life miserable and strikes her in front of visiting Venetian nobles. Meanwhile, Roderigo complains that he has received no results from Iago in return for his money and efforts to win Desdemona, but Iago convinces him to kill Cassio.
Roderigo unsuccessfully attacks Cassio in the street after Cassio leaves Bianca's lodgings, as Cassio wounds Roderigo. During the scuffle, Iago comes from behind Cassio and badly cuts his leg. In the darkness, Iago manages to hide his identity, and when Lodovico and Gratiano hear Cassio's cries for help, Iago joins them. When Cassio identifies Roderigo as one of his attackers, Iago secretly stabs Roderigo to death to stop him from revealing the plot. Iago then accuses Bianca of the failed conspiracy to kill Cassio.
Othello confronts a sleeping Desdemona. She denies being unfaithful, but he smothers her. Emilia arrives, and Desdemona defends her husband before dying, and Othello accuses Desdemona of adultery. Emilia calls for help. The former governor Montano arrives with Gratiano and Iago. When Othello mentions the handkerchief as proof, Emilia realizes what Iago has done, and she exposes him. Othello, belatedly realising Desdemona's innocence, stabs Iago (but not fatally), saying that Iago is a devil, but not before the latter stabs Emilia to death in the scuffle.
Iago refuses to explain his motives, vowing to remain silent from that moment on. Lodovico apprehends both Iago and Othello for the murders of Roderigo, Emilia, and Desdemona, but Othello commits suicide. Lodovico appoints Cassio as Othello's successor and exhorts him to punish Iago justly. He then denounces Iago for his actions and leaves to tell the others what has happened.
