"Twelfth night" is a play written by the most famous playwright William Shakespeare.
Twelfth night is a adventurous story of a brave girl named Viola who was washed up on the shores of Illyria. Anxious for her lost twin brother, she wants to know about the place. She wants to be the mate of Olivia. Her such desire made her disguise as a boy named Cesario and serve as a page to the Duke Orsino. Love-sick was he for the love of the noble lady, Olivia who locked herself in her castle like a nun in a convent. Serving Duke Orsino, she falls in love with him, herself.
With sorrow in her heart, she goes to Olivia's place in attempt to court her for the Duke, as per the Duke's commands. Unfortunately, she becomes an apple of Olivia's eyes. She even openly expresses her love for Cesario(Viola) and says that she can't live without her.
Then, Sebastian the twin brother of Viola appears in the story. He was actually living in the same place where Viola lived