Viola is a lady of Messaline. When dressed as a man she is identical to her twin brother Sebastian.
Shipwrecked on the coast of Illyria, convinced that her brother is drowned, she disguises herself as a man for her own safety, and seeks refuge at Orsino’s court, where she quickly becomes his favorite page under the name of Cesario. Sent to woo Olivia, she so impresses that lady, partly by her willingness to throw her script away, that Olivia falls in love with her, which is unfortunate seeing as she’s a woman and happens to be in love with Orsino. She defends her gender’s ability to love to Orsino, can be readily terrified at being forced to fight, and is quick-witted enough to realise that her brother may still be alive when Antonio recognises her. Despite this, she is confused enough when accused of having married Olivia that she does not consider that Sebastian may be an answer to the enigma. When her brother, Sebastian, arrives on the scene and all is unravelled, she admits to her gender and accepts Orsino’s proposal of marriage.