Iago is a subordinate of Othello’s and a captain in the Venetian defense forces. Othello passes him over for promotion in favor of the well-spoken, handsome Cassio, although Iago believes he is more experienced. Iago is determined to exact his revenge on Othello for this perceived insult, and also suspects that both Othello and Cassio have had sex with his wife Emilia, even though he has no evidence of this. Iago’s pride, jealousy, and misogyny combine into a destructive malice whose ultimate outcome even Iago can’t entirely predict. Throughout the play, he infects the other characters with his own negative traits, inciting them, and himself, to murder. In addition to driving Othello to kill Desdemona and Roderigo to attempt to kill Cassio, Iago himself kills Roderigo, as well as his wife, Emilia. He has a keen sense of other men’s insecurities and motivations, and in his plots, reduces women to prizes to be won, guarded, and discarded.

As one of Desdemona’s rejected suitors, Iago tricks Roderigo into giving Iago most of his money and manipulates him into ruining Cassio’s career before attempting to murder him. When Roderigo begins to suspect Iago is using him, Iago kills him. Roderigo’s lust for Desdemona, and Iago’s promise that he will help gratify it, drives most of his behavior.