Twelfth Night, or What You Will is a comedy by William Shakespeare, believed to have been written around 1601–02 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. Viola (who is disguised as a boy) falls in love with Duke Orsino, who in turn is in love with the Countess Olivia. Upon meeting Viola, Countess Olivia falls in love with her thinking she is a man. The play expanded on the musical interludes and riotous disorder expected of the occasion,with plot elements drawn from the short story “Of Apollonius and Silla” by Barnabe Rich, based on a story by Matteo Bandello. The first recorded performance was on 2 February 1602, at Candlemas, the formal end of Christmastide in the year’s calendar. The play was not published until its inclusion in the 1623 First Folio.