The jealous ensign in Shakespeare’s Othello is Iago.
Iago serves as Othello’s ensign, a military rank roughly equivalent to a junior officer who carries the unit’s flag. He resents Othello for promoting Cassio to lieutenant instead of him, and he turns that grievance into a calculated campaign of revenge. By presenting himself as “honest Iago,” he gains the trust of Othello and other characters while secretly manipulating them.
Iago’s plot depends on manufactured evidence and insinuation. He persuades Othello to suspect Desdemona of infidelity with Cassio, helping drive the tragedy toward murder and suicide. His motives are deliberately unstable: ambition, resentment, racial hostility, sexual suspicion and sheer destructive pleasure all appear in his speeches.
A common mix-up is Roderigo, another conspirator who loves Desdemona and follows Iago’s instructions. Cassio is the lieutenant whose promotion fuels Iago’s anger, while Montano is a governor of Cyprus. None of them is the jealous ensign.