In Shakespeare's play Othello, Iago is the antagonist. That is, he is the villain in the play Othello. He is the person who causes an action to occur which affects the other characters in the play. This action may not necessarily be a good thing. Iago is the catalyst for Othello's change. He is the reason behind Othello's changing views of his wife Desdemona, which results in the deaths of many of the characters in this tragedy. In order to understand the role Iago plays in destroying Othello, it is important to understand how Iago uses other characters in Othello to set his devious plot into motion. Iago successfully manipulates the characters involved to further his evil plans. He does this in such a way that the majority of the characters" perceptions of each other change dramatically. Thus leading to Othello's transformation and Othello's changing views and behaviour towards his beloved wife Desdemona. Iago firstly uses Roderigo, a Venetian gentleman, in love with Desdemona and then Cassio in the process of annihilating Othello. Cassio is Othello's Lieutenant. Other characters Iago exploit include his own wife Emilia and Desdemona herself. Iago goes to a lot of trouble to conquer Othello. When Iago's interaction with the other characters is understood then it can be perfectly recognised, acknowledged and understood how Iago causes Othello's perceptions of Desdemona to change so drastically and quickly. Roderigo is the first fall under Iago's spell of manipulation. Roderigo is convinced that Iago is genuine and does everything Iago tells him to. Iago easily convinces Roderigo to tell Desdemona's father, Brabantio, of Desdemona's elopement with a "moor". Iago and Roderigo tell Brabantio of Othello's marriage to Desdemona who rushes over to Othello to unsuccessfully reclaim his daughter. "An old black ram Is tupping your white ewe." (Act 1, Scene 1, Line 90). Brabantio's perceptions of both his daughter and Othello have changed.