"Don Carlos" is an opera composed by Giuseppe Verdi, based on the play by Friedrich Schiller. It tells the story of Don Carlos, the son of King Philip II of Spain, who is in love with Elizabeth of Valois, the wife of his father. The opera explores themes of love, political intrigue, and the struggle for freedom. The opera is set in the 16th century and features a rich orchestral score and powerful vocal performances. It is known for its complex characters and emotional depth, making it a significant work in the operatic repertoire. "Don Carlos" has multiple versions, with varying lengths and arrangements.