Bianca (Othello) confirms his wife's infidelity. This "evidence" completes Iago's manufactured case against Desdemona, and thereafter Othello is determined to murder both her and Cassio. In 5.1, Bianca arrives just after Cassio has been stabbed by Iago. She reacts with horror and concern. Iago, pretending to have just entered the scene, accuses Bianca of having been part of the group that attacked Cassio. Iago claims her emotional reaction is due to her being caught rather than concern for Cassio and gets her to admit that Cassio ate at her home earlier that evening. Both Iago and Emilia call her a prostitute, but
Othello (character) Othello kills his wife out of jealousy by strangling her, only to realize that his wife was faithful after Emilia reveals the truth, at which point he commits suicide. "Othello" has its source in the 1565 tale "Un Capitano Moro" from "Gli Hecatommithi" by Giovanni Battista Giraldi Cinthio. While no English translation of Cinthio was available in Shakespeare's lifetime, it is probable that Shakespeare knew both the Italian original and Gabriel Chappuy's 1584 French translation. Cinthio's tale may have been based on an actual incident occurring in Venice about 1508. It also resembles an incident described in the earlier tale