The most important element of Othello is the constant scheming and machinations of Iago, the title character's ensign. Apparently out of jealousy of Michael Cassio (who Othello gave a promotion instead of Iago,) Iago schemes to destroy Cassio and ultimately Othello and his young wife Desdemona. He skillfully manipulates all of the main characters, playing off of their vulnerabilities, especially Othello's jealousy. Iago's actions, and Othello's misguided trust in him, drive the plot forward, leading toward its tragic end. The plot iof Othello s complex, but there are few significant deviations from it, and there is little doubt that the most important element of the play is the almost ludicrously villainous Iago.