Iago is passed over for a promotion by his commander, Othello, a Moor and a general in the service of Venice, and he vows revenge. Othello has just married Desdemona, the daughter of Brabantio, a Venetian Senator, and Iago enlists the aid of Roderigo, a rejected suitor, to tell Desdemona's father about the marriage. Brabantio goes to seize his daughter but is interrupted by news of a Turkish attack on Cyprus. The Duke and the Senate convene, and after hearing Desdemona and Othello testify to their love for one another, they allow her to accompany him to Cyprus, which he will defend against the Turks. Iago, whom Othello regards as honest and trustworthy, is given charge of Desdemona on the journey.
             At Cyprus, Iago has Roderigo start a brawl, in which Cassio, Othello's lieutenant, wounds another man. Othello strips Cassio of his command, and Cassio goes to Desdemona to ask her to convince her husband to reinstate him. Iago, meanwhile, sets about convincing Othello that Desdemona has been unfaithful to him--with Cassio. Through innuendo and pretended honesty, Iago makes Othello almost mad with jealousy, until the Moor names him his lieutenant and makes him promise to help him kill Cassio and Desdemona.
             Desdemona has lost a handkerchief that Othello gave her as a love-token, and Emilia, Iago's wife, finds it and gives it to her husband. Iago plants the handkerchief in Cassio's house, then arranges for Othello to see Cassio give it to his mistress, Bianca. Othello is now convinced that Cassio has betrayed him with Desdemona, and that Cassio is flaunting his sexual conquest by giving Desdemona's handkerchief to a common whore. Othello begins abusing his wife in front of messengers from Venice, who are amazed to see this change in a man they thought to be noble.
             That night, Othello tells his wife to wait for him in bed and goes out to walk about the city. Iago has convinced Roderigo that if he kills Cassio, Desdemona will sleep with ...