[Verdi's Don Carlos was based upon Friedrich Schiller's play. The following article is a detailed look at the original source. - NMR]
NOTE: The complete text of the play can be found at:
Schiller called his Don Carlos, "A family portrait in a princely house". It took him four years to write it and he kept revising for eighteen years. In the end, he was unable to separate the domestic and political lives of the characters. As he wrote: "It was my intention to expose the shameful horrors of the Inquisition, and to revenge prostituted humanity....I wished to seize the poignard with which tragedy had hitherto only superficially touched men and thrust it home".
Don Carlos is twice the length of an ordinary play and on a much grander scale than Schiller's earlier works. It is written in blank verse in imitation of Shakespeare. While Schiller said he wanted to be true to history, the events of the play are certainly not. During the four years of writing, the emphasis for Carlos shifted from his love story to his commitment to free the Netherlands, and Posa assumed more and more importance. The one fictional character, he became the play's intellectual center. Of Posa Schiller wrote: "Like all great minds, he arose between darkness and light, an isolated apparition. He lived at a moment when heads were in confusion, prejudice fought reason, there existed an anarchy of beliefs. Yet the morning hour brought a glimmer of truth such was always the hour in which exceptional men were born".
Schiller's sources included Don Carlos, Nouvelle historique by César Vischard Saint-Real (1672) in which both Carlos and Don Juan develop a passion for Elizabeth. Saint-Real was definitely anti-Spanish. Another source was Robert Watson's History of the Reign of Philip II (ca. 1780), which is also anti-Philip.
In the very complex plot, there is a plethora of letters, secret messages, keys and misunderstandings. Among the characters which were cut from the opera are the Duke of Alva, a fictional Dominican monk, Domingo, and the Duke of Medina Sedonia (who speaks of the loss of the Spanish Armada about twenty years before this really happened).The passionate Princess Eboli already bears that title although she has just become engaged to Ruy Gómez, the real Prince Eboli. In reality they had already been married for almost ten years She may have had an affair with Philip (he loves her) and, as in the opera, she is in love with Don Carlos.
There are many differences between the play and the opera. Schiller mentions but does not show the auto-da-fé. Eboli joins Alva, and Domingo in a plot against Don Carlos; they want to prevent him from becoming king. Elizabeth is very inaccessible. She has a six-year-old daughter whom Alva and Domingo, to fan Philip's jealousy, insinuate is really Carlos's. When Carlos's letters to her are found, Philip accuses her of harlotry, and she threatens to flee to France with their daughter. Philip remarks that Carlos shuns his presence since he came back from Alcalá, but Carlos does plead with his father to love him. When Carlos asks to lead the army in Flanders, Philip insists it go to Alva. There are several references to the ghost of Charles V, once in secret vaults below the palace and once in the apartments of Elizabeth. Philip orders the ghost be found.
Posa refers to himself as a former playmate of the stripling Carlos who also speaks of their childhood years together. Posa and Philip had never met until Posa comes to him, swears his fealty and agrees to spy on Carlos. Philip gives Posa a secret warrant of arrest for Carlos, to be used when necessary. When he tells the King of the terrible conditions in Flanders and begs him to free the people from oppression, Philip warns him of the Inquisition. Posa arrests Carlos and detains Eboli. Alva releases Carlos, but he refuses to go, saying only the king can free him. Posa then comes to Carlos and begs forgiveness; he has a premonition he will die and says he is giving his life for the Prince. After Posa is shot, the King gives Carlos his sword back, but the prince accuses his father of the murder of his friend. A distraught King mourns Posa and tries to decide whether to kill Carlos or to let him escape. When the Inquisitor berates Philip for depriving the Inquisition of its victim (Posa), he hands Carlos over to him, and the curtain falls.