This article presents a reading of Gian Francesco Busenello's and Claudio Monteverdi's opera L'incoronazione di Poppea in light of seventeenth-century theatrical practices. Reconstructing the doubling plan from the opera's premiere in 1643 on the basis of contemporary doubling practices and the correspondence of the Ferrarese music patron Marquess Cornelio Bentivoglio, the author argues, adducing circumstantial evidence, that Ottavia and Drusilla were conceived as a double role for the operatic quick-change artist Anna Renzi. While Renzi is known to have created Ottavia, this part is half the size of all other roles written for her, which invariably involve dramatic, emotional and musical variety to a much greater extent than does Monteverdi's tragic Empress. Renzi was admired for her command of both tragedy and comedy, and the essay develops the hypothesis of the double role as an intertextual interpenetration of the title heroines from the pseudo-Senecan tragedy Octavia and Girolamo Bargagli's sixteenth-century comedy La pellegrina.