Orsino is Duke of Illyria. a powerful nobleman. Orsino is a bachelor, lovesick for the beautiful Lady Olivia, but finds himself becoming more and more fond of his handsome new page boy, Cesario, who is actually Viola, the daughter of a nobleman who knew Duke Orsino. Viola falls in love with Orsino, despite continuing to plead his case to Olivia. But then Olivia, under the impression that Viola was Cesario, falls in love with her. Later when Viola's twin brother Sebastian comes to Illyria, he is mistaken as Cesario by Olivia and is asked to marry her, to which he agrees. At the end of the play, when the confusion around the mistaken identities of Viola and her twin Sebastian is resolved, and Orsino comes to know Viola's true identity, he agrees to take Viola as his wife.