Act 1: Iago, Othello’s standard bearer and friend, wakes Brabantio, a Venetian senator and old friend of Othello’s. Iago informs Brabantio that his daughter, Desdemona, has eloped with Othello, a general in the Venetian army. Othello is put on trial by Brabantio and the Venetian Court. Desdemona and Othello publicly profess their love for each other and are forgiven by all but Brabantio. Othello is chosen to lead the Venetian army to defend Cyprus from the oncoming Turkish fleet.
Act 2: Othello defeats the Turks and is greeted by Desdemona in Cyprus. Also present is Cassio, Othello’s second lieutenant who helped Othello to woo Desdemona. Cassio gets drunk and brawls with Roderigo, Iago’s lackey who is lovesick for Desdemona, and gets ousted from the army by Othello.
Act 3: Cassio pleads with Desdemona to prevail upon Othello to reinstate him as his second lieutenant. However, Iago had slyly encouraged Cassio to speak privately to Desdemona about mending things with Othello. Iago then manipulates Othello into believing that Cassio and Desdemona’s meeting is about their secret love for each other. Othello swears to put Cassio and Desdemona to death for their betrayal.
Act 4: Iago continues to convince Othello of Desdemona’s unfaithfulness. Othello becomes so distraught that he suffers a seizure. Iago then plants Desdemona’s handkerchief, a gift from Othello, in Cassio’s room. Next, Iago stages a conversation with Cassio about Cassio’s courtesan, Bianca. Falling right into Iago’s trap, Othello misinterprets the conversation to be a lewd discussion of his wife. Othello loses his temper and strikes Desdemona out of rage. Othello threatens Emilia, Desdemona’s maid and Iago’s wife, to give him information about Desdemona and Cassio’s private meetings. Emilia truthfully denies all of Othello’s accusations.
Act 5: Othello believes that Cassio has been killed, having ordered the murder himself. Othello chooses to kill Desdemona and smothers her with a pillow in their marital bed. Emilia discovers them and confronts Othello with the truth about Iago. Despite the consequences of speaking out, Emilia tells Othello and others of Iago’s acts, and he kills her before being arrested. Othello, realizing the grim truth, apologizes to Cassio and kills himself, dying next to Desdemona.