Twelfth Night, or What You Will is a romantic comedy by William Shakespeare, believed to have been written around 1601-1602 as a Twelfth Night's entertainment for the close of the Christmas season. The play centres on the twins Viola and Sebastian, who are separated in a shipwreck. Twelfth Night is a fast-paced romantic comedy with several interwoven plots of romance, mistaken identities and practical jokes. Separated from her twin brother Sebastian in a shipwreck, Viola disguises herself as a boy, calls herself Cesario, and becomes a servant to the Duke Orsino.