Pierre Beaumarchais
In 1786, Wolfgang Amadeus Mozart composed an opera, "Le Nozze di Figaro", based on "The Marriage of Figaro", with a libretto by Lorenzo Da Ponte based on the play. Several composers including Paisiello in 1782 wrote operas based on "The Barber of Seville". Rossini's 1816 version is his most successful work and still often performed. In 1966, Darius Milhaud composed an opera, "La mère coupable", based on "The Guilty Mother".
Michel Carré
He went to Paris in 1840 intending to become a painter but took up writing instead. He wrote verse and plays before turning to writing libretti. He wrote the text for Charles Gounod's "Mireille" (1864) on his own, and collaborated with Eugène Cormon on Bizet's "Les pêcheurs de perles". However, the majority of his libretti were completed in tandem with Jules Barbier, with whom he wrote the libretti for numerous operas, including Camille Saint-Saëns's "Le timbre d'argent" (libretto written in 1864, first performed in 1877), Gounod's "Faust" (1859), "Roméo et Juliette" (1867), and Offenbach's "Les contes d'Hoffmann" (1881). As with the other libretti by Barbier and himself, these were adaptations of existing literary masterworks.