Operette in 3 acts by Johann Strauss II, premiered 1 March 1873 at the Theater an der Wien; book by Joseph Braun, sung text by Richard Genee. Sources: Operetten-Lexikon http://www.operetten-lexikon.info/?menu=248&lang=1 ("Der Carneval in Rom / Operette in 3 Akten / Musik von Johann Strauss / Text von Richard Genee und Joseph Braun / Urauffuehrung: 1. Maerz 1873 im Theater an der Wien") and German Wikipedia https://de.wikipedia.org/wiki/Der_Karneval_in_Rom . Title entered in the 1873 spelling used by the score and by the Staatsoperette Dresden, which revived the work in October 2004; Wikipedia modernises it to "Der Karneval in Rom". Added because a 2004 Dresden radio recording of it is being filed and findopera already holds the comparably rare Strauss operettas Blindekuh, Simplicius and Prinz Methusalem.