The play opens with Roderigo, a rich and dissolute gentleman, complaining to Iago, an ensign, that Iago has not told him about the secret marriage between
Desdemona, the daughter of a Senator named
Brabantio, and
Othello, a
Moorish general in the Venetian army. He is upset by this development because he loves Desdemona and had previously asked her father for her hand in marriage. Iago hates Othello for promoting a younger man named
Michael Cassio above him, and tells Roderigo that he plans to use Othello for his own advantage. Iago is also angry because he believes, or at least gives the pretence of belief, that Othello slept with his wife Emilia. Iago denounces Cassio as a scholarly tactician with no real battle experience; in contrast, Iago is a battle-tested soldier. By emphasizing Roderigo's failed bid for Desdemona, and his own dissatisfaction with serving under Othello, Iago convinces Roderigo to wake Brabantio, Desdemona's father, and tell him about his daughter's
elopement. Iago sneaks away to find Othello and warns him that Brabantio is coming for him.