One of the primary conflicts of the first half of Shakespeare’s Twelfth Night is the love triangle between Duke Orsino, Olivia and Viola / Cesario. Viola, disguised as Cesario, is in love with Duke Orsino. Unfortunately for Viola, Orsino is in love with Olivia and has employed Viola, disguised as Cesario, to woo Olivia for the Duke. Orsino believes the Viola is a young man, Cesario, and therefore knows nothing of Viola’s love.
Viola, disguised as Cesario, approaches Olivia and attempts to win her love for Duke Orsino. However, Olivia does not love the Duke and will not return his love. Instead, Olivia falls in love with Cesario, who the audience knows is really Viola. This complicates matters because Cesario is really Viola, a woman.
There does not appear to be a resolution to this conflict until Act IV, Scene 1. In this scene, Feste the Clown meets Sebastian, Viola’s twin brother. Viola though Sebastian died at sea. Feste, believing Sebastian to be Cesario, takes him to see Olivia. At Olivia’s house, Sebastian is attacked twice, first by Sir Andrew and shortly after by Sir Toby. Sebastian, overcome by confusion, asks “Are all the people mad?” (4.1.27). Sebastian, who does not know his sister is alive or that he has been caught in a game of mistaken identity, does not know how to react. However, Olivia enters the scene and quickly takes charge. She begs Sebastian, who she also thinks is Cesario, to come into her house and pleads that Sebastian be “rul’d by me!” (4.1.64). Sebastian, although he does not know Olivia, quickly consents.
This initial meeting between Olivia and Sebastian works to resolve the love triangle conflict. Their encounter completes the four angles of the love plot (Olivia / Sebastian, Viola / Orsino). Olivia mistakes Sebastian for Cesario, the man she loves. Off stage, Olivia and Sebastian are married, an action that resolves the conflict and allows possibility for the relationship between Viola and Orsino.