Berlioz had been interested in setting Shakespeare's comedy since his return from Italy in 1833, but only composed the score of Béatrice et Bénédict following the completion of Les Troyens in 1858.

It is the first notable version of Shakespeare's play in operatic form, and was followed by works by, among others, Árpád Doppler, Paul Puget, Charles Villiers Stanford, and Reynaldo Hahn.

[3] Berlioz biographer David Cairns has written: "Listening to the score's exuberant gaiety, only momentarily touched by sadness, one would never guess that its composer was in pain when he wrote it and impatient for death".

[4] Berlioz described the premiere of Béatrice et Bénédict as a "great success" in a letter to his son Louis; he was particularly taken with the performance of Charton-Demeur (who would create the role of Didon in Les Troyens in Paris a year later) and noted that the duo which closes the first half elicited an "astonishing impact".

[5] Although it continued to be staged occasionally in German cities in the years after the premiere, the first performance in France only took place on 5 June 1890 at the Théâtre de l'Odéon, 21 years after its composer’s death, promoted by Élisabeth Greffulhe's Société des Grandes auditions musicales de France, conducted by Charles Lamoureux, and with Juliette Bilbaut-Vauchelet and Émile Engel in the lead roles.

The act ends with a nocturne for Héro and Ursule – a slow duo in 68 which W. J. Turner described as "a marvel of indescribable lyrical beauty"[14] and which Grove compares to "Nuit d'ivresse" in Les Troyens.

[2] Next, in an extended air across a wide melodic span, Béatrice acknowledges that she too is powerless against love and in the following trio (added after the premiere) Héro and Ursule join her to extol the joys of marriage.

With Héro and Ursule she sings of the happiness of a bride about to be wed. As she turns to leave she is met by Bénédict, prompting an exchange in which they both attempt to conceal their love for each other.