Der Rosenkavalier (The Knight of the Rose or The Rose-Bearer), Op. 59, is a comic opera in three acts by Richard Strauss to an original German libretto by Hugo von Hofmannsthal. It is loosely adapted from Louvet de Couvrai's novel Les amours du chevalier de Faublas and Molière's comedy Monsieur de Pourceaugnac. It was first performed at the Königliches Opernhaus in Dresden on 26 January 1911 under the direction of Max Reinhardt, with Ernst von Schuch conducting. Until the premiere, the working title was Ochs auf Lerchenau. (The choice of the name Ochs is not accidental, as "Ochs" means "ox", which describes the Baron's manner.)
The opera has four main characters: the aristocratic Marschallin; her 17-year-old lover, Count Octavian Rofrano; known as Quinquin, her brutish cousin Baron Ochs; and Ochs's prospective fiancée, Sophie von Faninal, the daughter of a rich bourgeois. At the Marschallin's suggestion, Octavian acts as Ochs's Rosenkavalier by presenting a ceremonial silver rose to Sophie. But Octavian and Sophie fall in love on the spot, and soon devise a comic intrigue to extricate Sophie from her engagement, with help from the Marschallin, who then yields Octavian to Sophie. Though a comic opera, the work incorporates weighty themes (particularly through the Marschallin's character arc), including infidelity, aging, sexual predation, and selflessness in love.
Der Rosenkavalier is notable for showcasing the female voice, as its protagonists (light lyric soprano Sophie, mezzo-soprano Octavian, and the mature dramatic soprano Marschallin) are written to be portrayed by women, who share several duets as well as a trio at the opera's emotional climax. Some singers have performed two or even all three of these roles over the course of their careers.
There are many recordings of the opera and it is regularly performed.