The play opens in Venice, Italy, at night. Iago, General Othello's ensign, and Roderigo, who is in love with Desdemona, are on the street outside of the home of Brabantio, Desdemona's father. Iago tells Roderigo of his hatred for Othello, primarily because Othello has promoted Michael Cassio ahead of Iago. They call out to Brabantio, telling him in crude language that his daughter is having a sexual encounter with Othello. Brabantio, enraged, goes with his servants to find the couple. Meanwhile, Iago goes to Othello to warn him of Brabantio's anger.
In the next scene, the duke and the senators discuss the Turkish threat on Cyprus. Brabantio, Othello, Cassio, and Roderigo, all enter and Brabantio levels his charges against Othello. Othello replies that he has not stolen Desdemona but has rather legally married her, although without her father's consent. Desdemona is sent for, and when she arrives, she concurs with Othello's summary of their relationship. The duke recognizes their marriage and tells Othello that he must go to Cyprus to defend against the Turks. Othello asks that his wife accompany him, and Desdemona says that she wants to go with him as well.
The act closes with an exchange between Iago and Roderigo. Iago says that Othello will soon change his mind and that Iago will help Roderigo win Desdemona. After Roderigo's exit, Iago reveals to the audience how much he hates Othello and Cassio and that he plans to ruin both of them.
Act 2 opens in Cyprus in a storm. The Turks have lost their entire fleet in the tempest. Ultimately, all the characters arrive in Cyprus, and Othello and Desdemona are lovingly reunited. Iago hatches his plot with Roderigo and instructs Roderigo to make Cassio angry this evening after Iago makes Cassio drunk.
In the next scene, Othello leaves to celebrate his nuptials with Desdemona. After Othello's departure, Iago manages to get Cassio to drink more than he should. As a consequence, when...