Pope Joan, thought for centuries to be a fact, is today regarded as fiction. During the Middle Ages, the story goes, an erudite woman disguised herself as a man, ascended within the church hierarchy, and was elected pope. The truth came out when she gave birth to a child during a church procession. Undeniably irresistible, the story of Pope Joan has been retold in books, onstage, and in film. For its 80th anniversary, the Greek National Opera commissioned an opera on the subject from the composer Yiorgos Vassiliandonakis. The libretto is based on The Papess Joanne, an 1866 novel by the Greek writer Emmanuel Rhoides, a book vilified at home but admired in the West. Pope Joan is in two acts, with 15 scenes. —L.J.