Giuseppe Verdi’s (1813-1901) grand and full-length opera “Don Carlos” is based on Friedrich Schiller’s drama “Don Karlos, Infant of Spain”. The French original of 1867 was first performed in Paris, belongs to the genre of the Grand Opéra, was Verdi’s third commissioned work for the Paris Opera and has five acts; a second, shorter version was not performed until 17 years later at the Teatro alla Scala in Milan. Unlike the first version, this one contains four acts and has an Italian libretto instead of a French one. This also explains the two different spellings of the work: "Don Carlos" / "Don Carlo".
It is now known that seven different versions of the opera exist. After massive criticism, the composer was repeatedly forced to make changes and cuts to his work, as the first version, with almost five hours of playing time, was too lengthy even for the Parisian audience - an educated and music-loving audience that was quite used to the lengthy duration of the large-scale and epic Grand Opéra. After the second version had been favoured until the end of the 20th century, theatres today tend to favour the first, longer version, since in it the plots and motivations of the characters can be presented much better and more coherently.