Iago (Frank Finlay) tricks Othello (Laurence Olivier) into believing his young wife Desdemona has been having an affair with Cassio (Derek Jacobi). Othello strangles Desdemona (Maggie Smith).
Iago's wife Emilia realizes what her husband has done and tells the leaders of Venice. Iago kills her, and is arrested. A grief-stricken Othello stabs himself.
Thanks John L!