Iago is a leader in Othello’s army. He has a reputation for being honest and truthful. Iago becomes upset with Othello when Othello promotes Michael Cassio to a position that Iago believes he deserves. Iago believes that he is more qualified for the position because he (Iago) has battle experience while Cassio is simply a scholarly tactician.
In his anger, Iago uses his leadership position and reputation for honesty to begin a smear campaign against Othello and Cassio. Iago never really tells direct lies, but passes along innuendo and rumors to other team members. These rumors take on a life of their own and result in Othello becoming so paranoid and suspicious he demotes Cassio, kills Desdemona and takes his own life. In the end, Iago is taken away to face his punishment.
