Octavian, a handsome youth, is taking a passionate leave of the Princess, whose husband, a Field Marshal, is away on military duty. Octavian is loath to go, the Princess, equally loather to have him depart. For the Princess cannot conceal from herself that in spite of Octavian's present love for her, the disparity in their ages soon will cause him to look to women younger than herself for love.
There is a commotion beyond the door of the Princess's suite of rooms. One of her relatives, the vulgar Baron Ochs von Lerchenan, wishes to see her. The servants remonstrate with him that the hour is much too early, but he forces his way in. Taking alarm, and in order to spare the Princess the scandal of having him discovered with her, Octavian escapes into an inner room where he disguises himself in the attire of a chambermaid, a rôle which his youthful, beardless beauty enables him to carry out to perfection.
Von Lerchenan has come to inquire of the Princess if, as she promised, she has sent a Knight of the Rose with an offer of his hand to Sophie, daughter of the wealthy, recently ennobled Herr von Faninal. A Knight of the Rose was chosen at that period as a suitor by proxy to bear a silver rose, as a symbol of love and fidelity, to the lady of his principal's choice. Unfortunately the Princess's passion for Octavian has entirely diverted her thoughts from Lerchenan's commission. He, however, consoles himself by flirting with the pretty chambermaid, Octavian, whose assumed coyness, coupled with slyly demure advances, charms him. Before this, however, he has lost his temper, because he has been unable to engage the Princess's attention amid the distractions provided by her morning levee, at which she receives various petitioners—a singer, Valzacchi, and Annina, who are Italian intriguers, three noble orphans, and others. This levee, together with the love intrigues and the looseness of manners and morals indicated by the plot, is supposed in a general way to give to the piece the tone of the rococo period in which the story is laid. The scene is a lively one.
Lerchenan is appeased not only by the charms of the supposed chambermaid, who waits on the Princess and her relative at breakfast, but also because he is so eager to make a rendezvous with her. Octavian in his disguise understands so well how to lead Lerchenan on without granting his request, that he forgets the cause of his annoyance. Moreover the Princess promises that she presently will despatch a Knight of the Rose to the daughter of the wealthy Faninal whose wealth, of course, is what attracts Lerchenan. The Princess chooses Octavian to be the Knight of the Rose. Later she regrets her choice. For after the handsome youth has departed on his mission, and she is left alone, she looks at herself in the glass. She is approaching middle age, and although she still is a handsome woman, her fear that she may lose Octavian, to some younger member of her sex, cannot be banished from her thoughts.
Act II. Salon in the house of Herr von Faninal. This lately ennobled nouveau rich considers it a great distinction that the Baron von Lerchenan, a member of the old nobility, should apply for the hand of his daughter. That the Baron only does it to mend his broken fortunes does not worry him, although his daughter Sophie is a sweet and modest girl. Inexperienced, she awaits her suitor in great agitation. Then his proxy, Octavian, comes with the silver rose to make the preliminary arrangements for his "cousin," Baron von Lerchenan. Octavian is smitten with the charms of the girl. She, too, is at once attracted to the handsome young cavalier. So their conversation imperceptibly has drifted into an intimate tone when the real suitor enters. His brutal frankness in letting Sophie comprehend that he is condescending in courting her, and his rude manners thoroughly repel the girl. Octavian meanwhile is boiling with rage and jealousy. The girl's aversion to the Baron increases. The two men are on the point of an outbreak, when Lerchenan is called by a notary into an adjoining room where the marriage contract is to be drawn up. Sophie is shocked at what she has just experienced. Never will it be possible for her to marry the detested Baron, especially since she has met the gallant Octavian. The two are quick in agreeing. Sophie sinks into his arms.
At that moment there rush out from behind the two large chimney pieces that adorn the room, the intriguers, Valzacchi and his companion Annina, whom Lerchenan has employed as spies. Their cries bring the Baron from the next room. The staff of servants rushes in. Octavian tells the Baron of Sophie's antipathy, and adds taunt to taunt, until, however reluctant to fight, the Baron is forced to draw his sword. In the encounter Octavian lightly "pinks" him. The Baron, a coward at heart, raises a frightful outcry. There ensues the greatest commotion, due to the mix-up of the servants, the doctor, and the rage of Faninal, who orders Sophie to a convent when she positively refuses to give her hand to Lerchenan. The latter, meanwhile, rapidly recovers when his wound has been dressed and he has drunk some of Faninal's good wine.
Octavian is determined to win Sophie. For that purpose he decides to make use of the two intriguers, who are so disgusted by the niggardly pay given them by the Baron, that they readily fall in with the plans of the brilliant young cavalier. After the crowd has dispersed and the Baron is alone for a moment, Annina approaches and hands him a note. In this the Princess's chambermaid promises him a rendezvous. Lerchenan is delighted over the new conquest he believes himself to have made.
Act III. A room in an inn near Vienna. With the help of Valzacchi and Annina, who are now in the service both of the Baron and of Octavian, but are more prone to further the latter's plans because he pays them better, Octavian has hired a room in an inn. This room is fitted up with trapdoors, blind windows and the like. Here, at the suggestion of the intriguers, who have the run of the place and know to what uses the trick room can be put, Lerchenan has made his rendezvous for the evening with the pretty chambermaid. Octavian, in his girl's clothes, is early at the place.
Between the Baron and the disguised Octavian, as soon as they are alone, a rude scene of courtship develops. Octavian is able to hold him off skilfully, and gradually there is unfolded the mad web of intrigue in which the Baron is caught. Strange figures appear at the windows. Lerchenan, ignorant, superstitious, thinks he sees ghosts. Suddenly what was supposed to be a blind window, bursts open, and a woman dressed in mourning rushes in. It is the disguised intriguante, Annina, who claims to be the deserted wife of Lerchenan. Innkeeper and servants hurry in. The clamour and confusion become more and more frantic. Finally the Baron himself calls for the police, without thinking what a "give away" it may be for himself. When the Commissary of Police arrives, to save his face, he gives out that his companion, the supposed chambermaid, is his affianced, Sophie von Faninal. That, however, only adds to the confusion, for Octavian's accomplices have sought out Faninal and invited him on behalf of the Baron to come to the inn. In his amazement the Baron knows of no other way out of the dilemma save to act as if he did not know Faninal at all, whereupon the latter, naturally, is greatly angered. When the confusion is at its height the Princess suddenly appears. A lackey of the Baron, seeing his master in such difficulties, has run to her to ask for her powerful protection. She quickly takes in the whole situation; and however bitterly Octavian's disaffection grieves her, she is a clever enough woman of the world to recognize that the time for her to give him up has come. The threads now quickly disentangle themselves. The Baron leaves, Octavian and Sophie are forgiven, and Herr von Faninal feels himself fully compensated for all he has been through, because he is to be driven home beside the Princess in her carriage.