The play opens in the powerful city state of Venice, famous as a center of trade and banking and for its military might. It is in the early hours of the morning, and two men — Roderigo, a young gentleman and former suitor of Senator Brabantio's daughter Desdemona, and Iago, an ensign who claims to have been passed over for promotion by Othello — are outside Senator Brabantio's house to tell him the news of his daughter's elopement with Othello, the Moor.
After sharing the news of the secret marriage in words calculated to alarm him, the treacherous and vindictive Iago quickly departs, leaving Roderigo to confirm the story. Feigning friendship and concern, Iago then meets with Othello and tells him of Brabantio's reaction. Brabantio, Othello, and Desdemona appear before the Duke of Venice. Although Brabantio accuses Othello of seducing his daughter by witchcraft, Othello explains that he won Desdemona by telling her his adventures, and Desdemona, called to testify, convinces the senators that she has freely gone with Othello and married him for love.
The Duke appoints Othello as general of the defense forces against the Turks, and he must leave for Cyprus immediately. Desdemona requests permission to accompany Othello to Cyprus. With the Duke's permission, Othello arranges for Desdemona to follow him later in another ship with Iago, whom he mistakenly believes is a trusted friend, and Iago's wife, Emilia. Iago convinces Roderigo that Desdemona will soon tire of Othello and that he should follow her to Cyprus. To himself, Iago decides to make use of Cassio, the man he deeply resents and who received the promotion he himself wanted, as the instrument to destroy Othello.
