Geneviève de Brabant is an opéra bouffe, or operetta, by Jacques Offenbach, first performed in Paris in 1859. The plot is based on the medieval legend of Genevieve of Brabant. For the 1867 version two additional characters, men-at-arms were added to Act 2 and given a comic duet, in English-speaking countries widely known as the "Gendarmes' Duet" or the "bold gendarmes", from H. B. Farnie's English adaptation. As well as being a popular performance piece, it formed the basis for the U.S. "Marines' Hymn".