<P> The play is believed to have drawn extensively on the Italian production Gl'ingannati (or The Deceived Ones), collectively written by the Accademia degli Intronati in 1531 . It is conjectured that the name of its male lead, Orsino, was suggested by Virginio Orsini, Duke of Bracciano, an Italian nobleman who visited London in the winter of 1600 to 1601 . </P> <P> Another source story, "Of Apollonius and Silla", appeared in Barnabe Riche's collection, Riche his Farewell to Militarie Profession conteining verie pleasaunt discourses fit for a peaceable tyme (1581), which in turn is derived from a story by Matteo Bandello . </P> <P> "Twelfth Night" is a reference to the twelfth night after Christmas Day, called the Eve of the Feast of Epiphany . It was originally a Catholic holiday and therefore, like other Christian feast days, an occasion for revelry . Servants often dressed up as their masters, men as women and so forth . This history of festive ritual and Carnivalesque reversal, based on the ancient Roman festival of Saturnalia at the same time of year (characterized by drunken revelry and inversion of the social order; masters became slaves for a day, and vice versa), is the cultural origin of the play's gender confusion - driven plot . The actual Elizabethan festival of Twelfth Night would involve the antics of a Lord of Misrule, who before leaving his temporary position of authority, would call for entertainment, songs and mummery; the play has been regarded as preserving this festive and traditional atmosphere of licensed disorder . This leads to the general inversion of the order of things, most notably gender roles . The embittered and isolated Malvolio can be regarded as an adversary of festive enjoyment and community, led by Sir Toby Belch, "the vice-regent spokesman for cakes and ale" and his partner in a comic stock duo, the simple and constantly exploited Sir Andrew Aguecheek . </P> <P> The full title of the play is Twelfth Night, or What You Will . Subtitles for plays were fashionable in the Elizabethan era, and though some editors place The Merchant of Venice's alternative title, The Jew of Venice, as a subtitle, this is the only Shakespearean play to bear one when first published . </P>

Where did the name twelfth night come from