Don Carlo which debuted in 1867, ranks among the composer's most complex and challenging works. Based on the verse play by Schiller about tragic love and intrigue at the court of Philip II of Spain, the opera features a rich assortment of memorable characters and dramatic situations. Conflicts of a political sort abound in the libretto by Mery and Du Locle; Don Carlo is in love with Elizabeth de Valois, who has become the wife of his father, King Philip II, as the result of a political marriage. Furthermore, the Marquis de Posa, Don Carlo’s best friend, is wanted by the Grand Inquisitor because he is a 'freethinker.' Philip discovers his wife's infidelity and must decide what to do about his son while the Grand Inquisitor asserts his power over him.
This is the Schirmer Edition of the Libretto, in the original Italian with an English translation by Walter Ducloux.