Droit du seigneur
In Mozart's "The Marriage of Figaro", which premiered in 1786 with a libretto by Lorenzo Da Ponte, the comic plot revolves around the successful efforts of the young bride and groom, Figaro and Susanna, to block the efforts of the unfaithful Count Almaviva to seduce Susanna. To achieve his aim, the frustrated Count threatens to reinstitute "droit du seigneur". It was based on a play by Pierre Beaumarchais.
Nicolas-François Guillard
Nicolas-François Guillard (16 January 1752 – 26 December 1814) was a French librettist. He was born in Chartres and died in Paris, the recipient of a government pension in recognition of his work writing librettos. He was also on "Comité de Lecture" of the Paris Opéra. One of the foremost of the French librettist of his generation, he wrote libretti for many noted composers of the day, including Salieri ("Les Horaces") and in particular Sacchini ("Œdipe à Colone", amongst many others). His most famous work is "Iphigénie en Tauride", his first libretto, set by Gluck after the composer had initially rejected it. Gluck collaborated with Guillard to heavily recast the libretto, not only to suit Gluck's artistic preferences, but also to accommodate pre-existing music that Gluck borrowed, both from himself and from other composers, when composing the opera.