When Iago tells Othello Cassio slept with her.
Cassio and Desdemona know each other through their connection to Othello. Cassio is Othello's lieutenant, and Desdemona is Othello's wife. Their acquaintance grows as Desdemona advocates for Cassio after he is dismissed from his position, seeking to restore his honor and reputation in Othello's eyes.
If Desdemona asked a favour on Cassio's behalf, it would look to Othello like she was doing it out of an improper love for Cassio. The harder she argues, the more suspicious it seems to Othello.
Iago sets out to trap Othello by several means. He persuades Desdemona to plead for Cassio and persuades Othello that Desdemona pleading for Cassio proves she is in love with him. He steals the handkerchief, persuades Othello that she has given it away to Cassio, then gives it to Cassio himself. He gets lucky as Cassio gives it to Bianca and she returns it in Othello's sight. He talks to Cassio about Bianca, telling Othello who can see (but not hear) that he is talking about Desdemona. All of this circumstantial evidence bolsters the outright lies that Iago tells about Cassio admitting to having an affair with Desdemona.
The advice that overwhelmed Othello was to kill Desdemona and he will take care of Cassio
Because Othello is unsure of Desdemona's actions. He is afraid of losing Desdemona to Cassio.
Primarily the fact that Iago has suggested to him that that is what is being talked about. By this point, Iago has got Othello into such a state he cannot interpret anything Cassio or Desdemona does as being innocent.
Emilia overhears Othello and Desdemona discussing Cassio. Desdemona is pleading on Cassio's behalf to Othello, hoping to persuade him to reinstate Cassio as his lieutenant. In the conversation, Desdemona is trying to help Cassio regain his position in Othello's esteem.
Cassio and Desdemona know each other through their connection to Othello. Cassio is Othello's lieutenant, and Desdemona is Othello's wife. Their acquaintance grows as Desdemona advocates for Cassio after he is dismissed from his position, seeking to restore his honor and reputation in Othello's eyes.
If Desdemona asked a favour on Cassio's behalf, it would look to Othello like she was doing it out of an improper love for Cassio. The harder she argues, the more suspicious it seems to Othello.
cassio,bianca,othello,desdemona,lodovico
Iago had lied to Othello and convinced him that Desdemona was secretly having sex with Cassio.
The advice that overwhelmed Othello was to kill Desdemona and he will take care of Cassio
Iago sets out to trap Othello by several means. He persuades Desdemona to plead for Cassio and persuades Othello that Desdemona pleading for Cassio proves she is in love with him. He steals the handkerchief, persuades Othello that she has given it away to Cassio, then gives it to Cassio himself. He gets lucky as Cassio gives it to Bianca and she returns it in Othello's sight. He talks to Cassio about Bianca, telling Othello who can see (but not hear) that he is talking about Desdemona. All of this circumstantial evidence bolsters the outright lies that Iago tells about Cassio admitting to having an affair with Desdemona.
Because Othello is unsure of Desdemona's actions. He is afraid of losing Desdemona to Cassio.
Oversimplifying greatly ... Othello is a dark-skinned African Muslim (a "Moor") who is a high-ranking and hot-tempered general in the army of Venice, Italy. Cassio is Othello's trusted lieutenant. Desdemona is Othello's girlfriend, whom he marries early in the story. Iago (ee-ah-go) is a deviously sly soldier in Othello's army; he is jealous and bitter and wants to destroy Othello, because Othello has chosen Cassio to be his lieutenant instead of choosing Iago. Roderigo is another soldier who Iago easily manipulates to do his bidding. Everyone else in the story takes part in action that revolves around these 5 main characters. Iago tries to get Desdemona's father and the Duke of Venice to believe that Othello engaged in sorcery and kidnapping to get Desdemona to marry him, but that doesn't work. Fortunately for Iago, Othello doesn't realize that Iago is out to get him. Iago gets Cassio drunk, gets Roderigo to pick a fight with Cassio, and then convinces Othello that Cassio started the fight. Othello strips Cassio of his rank. Iago convinces Cassio that Othello's wife Desdemona can help convince Othello to give Cassio his rank back. Iago helps Cassio arrange a secret meeting with Desdemona. Then Iago convinces Othello that Cassio and Desdemona are having a love affair behind his back. Iago convinces Roderigo to kill Cassio, but Cassio is only wounded. Iago kills Roderigo so he can't tell anyone that Iago put him up to the murder attempt. In a fit of jealous rage, Othello smothers Desdemona who he believes has been having sex with Cassio. Cassio, Iago and others arrive at the scene of Desdemona's murder. Othello repents of his fit of temper that has caused him to kill his beloved wife. Desdemona's maid reveals that Iago made her set up false evidence that led Othello to his tragic incorrect conclusion. Iago kills the maid. Othello stabs Iago but only wounds him. Othello begs Cassio to forgive him for his unfounded jealousy, which he does. OMG, the dead Roderigo has left a letter fully incriminating the villainous Iago, who is led away to what we assume is torture and a gruesome death. Othello, crushed by having allowed Iago to lead him to ruin, gives a final speech and commits suicide with his dagger. Everyone comes back to life and bows to the audience, who are weeping and applauding.
Iago tells Cassio that he must persuade Othello to reinstate him. He says "the general's wife is now our general" and so the best way to persuade Othello is to get Desdemona to plead on Cassio's behalf. Since Iago has also told Othello that Desdemona and Cassio are having an affair, the harder Desdemona pleads, the worse it is going to look for both her and Cassio.
While Othello is hiding, Iago and Cassio discuss Desdemona. Iago uses this opportunity to manipulate Cassio into speaking favorably about Desdemona, knowing that Othello is eavesdropping. This conversation plays a crucial role in Iago's scheme to incite jealousy in Othello regarding Desdemona's loyalty.