A DOLL'S HOUSE is a three-act play in prose by Henrik Ibsen. It premiered at the Royal Theatre in Copenhagen, Denmark, on 21 December 1879. The play is significant for its critical attitude toward 19th century marriage norms. In 2006, A Doll's House held the distinction of being the world's most performed play. UNESCO has inscribed Ibsen's autographed manuscripts of A Doll's House on the Memory of the World Register in 2001, in recognition of their historical value.