Twelfth Night is a comedy play written by William Shakespeare. The story follows a young woman named Viola who disguises herself as a man named Cesario after being shipwrecked in Illyria. She falls in love with Duke Orsino, who in turn is in love with Countess Olivia. However, Olivia falls in love with Cesario, not knowing that he is actually Viola in disguise. The play is filled with mistaken identities, love triangles, and comedic misunderstandings.