VALENTIN               Mme. PAULINE VIARDOT. 
MARGUERITE DE VALOIS   Mme. CASTELLAN. 
URBAIN                 Mlle. ALBONI. 
COUNT DE ST. BRIS      Sig.  TAMBURINI. 
COUNT DE NEVERS        Sig.  TAGLIAFICO. 
RAOUL DE NANGIS        Sig.  MARIO. 
MARCEL                 Sig.  MARINI.

The action of the opera passes in 1572, the first and second acts in Touraine, and the remainder in Paris.  The first act opens on a scene of revelry in the salon of Count de Nevers, where a number of noblemen, among them Raoul de Nangis, a Protestant, accompanied by his faithful old Huguenot servant, Marcel, are present, telling stories of their exploits in love.  Marguerite de Valois, the betrothed of Henry IV., for the sake of reconciling the dispute between the two religious sects, sends her page to De Nevers’s salon and invites Raoul to her chateau.  When he arrives, Marguerite informs him of her purpose to give him in marriage to a Catholic lady, daughter of the Count de St. Bris.  Raoul at first consents; but when Valentin is introduced to him and he discovers her to be a lady whom he had once rescued from insult and who had visited De Nevers in his salon, he rejects the proposition, believing that her affections have been bestowed upon another, and that his enemies are seeking to entrap him.  St. Bris challenges Raoul for the affront, but the Queen disarms the angry combatants.  Valentin is now urged to marry Count de Nevers, and begs that she may pass the day in prayer in the chapel.  Meanwhile Count de St. Bris, who has been challenged by Raoul, forms a plot for his assassination, which is overheard by Valentin from within the chapel.  She communicates the plot to Marcel, who lies in wait with a party of Huguenots in the vicinity of the duel, and comes to Raoul’s rescue when danger threatens him.  A general combat is about to ensue, but it is suppressed by Marguerite, who suddenly appears upon the scene.  Raoul thus discovers that he owes his life to Valentin, and that her visit to De Nevers was to induce him to sever the relations between them, as she was in love with Raoul.  The announcement comes too late, for the marriage festivities have already begun.  Raoul visits her for the last time.  Their interview is disturbed by the approach of De Nevers, St. Bris, and other Catholic noblemen, who meet to arrange the details of the plot conceived by Catherine de Medicis for the slaughter of the Huguenots on St. Bartholomew’s Eve.  Valentin hurriedly conceals Raoul behind the tapestries, where he overhears their plans and witnesses the conjuration and the blessing of the swords, as well as the refusal of the chivalrous De Nevers to engage in murder.  After the conspirators have departed, Raoul and Valentin have a long and affecting interview, in which he hesitates between love and honor, Valentin striving to detain him lest he may be included in the general massacre.  Honor at last prevails, and he joins his friends just before the work of slaughter begins.  He rushes to the