The Sultana of Constantinople. At the slave market, Don Juan converses with an Englishman named John Johnson, telling him of his lost love Haidée, whereas the more experienced John tells him of having to flee from his third wife. A black eunuch from the harem, Baba, buys the infidel slaves Juan and John, and takes them to the palace of the sultan. Taking them to an inner chamber, Baba insists that Don Juan dress as a woman, and threatens castration if Juan resists that demand. Finally, Juan is taken into an imperial hall to meet the sultana, Gulbeyaz, a beautiful, twenty-six-year-old woman, who is the fourth, last, and favourite wife of the sultan.