In the 16th century Spain, the bandit Ernani is in love with Elvira, who is to be married to an elderly man against her will. The King of Spain also loves Elvira. Jealousy, revenge, forgiveness, and the sanctity of the oath lead the characters through meandering roads with love and death as their suite. Verdi’s fifth opera was inspired by the play Ernani of Victor Hugo, a strange story of three men who all love one woman.
1519, Aragon, Aachen and Zaragoza.
The bandit Ernani, who is in fact Aragon’s Don Giovanni in disguise, is hiding in the mountains of Aragon with other bandits while he plans his revenge against Don Carlo, King of Spain, for murdering his father. Ernani needs help – he is in love with Elvira, the niece and bride-to-be of the old Don Ruy Gomez de Silva. Ernani’s compatriots promise to help him kidnap Elvira.
Meanwhile, in Silva’s palace Elvira dreams of fleeing with her beloved Ernani. Don Carlo, who is also in love with her, comes to her. Elvira rejects his advances and the King attempts to kidnap her. Ernani arrives, and the two rivals threaten each other. Silva is disappointed to encounter his bride with two strangers and challenges them to duel. When Riccardo, the King’s squire arrives, Silva, Elvira’s nurse Giovanna and Silva’s squire Jago, realise that the King himself stands before them. Don Carlo does not reveal Ernani’s true identity and urges him to flee.
The Silva palace is preparing for the wedding. Disguised as a pilgrim, Ernani arrives at the palace and asks for shelter. Silva welcomes him and introduces his guest to his betrothed. Upon seeing Elvira in her wedding dress the distraught pilgrim reveals himself as Ernani and allows himself to be handed over to the King. However, de Silva keeps his promise to care for the safety of his guest. Left alone with Ernani, Elvira explains that she had thought her beloved to be dead and had planned to end her of life shortly before the wedding. Silva discovers the lovers embracing and, upon the arrival of the King, promises to take revenge on Ernani, yet continues to hide him in his palace. When Silva refuses to release Ernani, the King takes Elvira with him as a hostage. After the King has left with Elvira, Silva challenges Ernani to a duel, but Ernani reveals to him that Don Carlo is also in love with Elvira. They agree that Ernani may be free to go and take his revenge on the King, but that his life will end at the sounding of the hunting horn.
Aachen. Don Carlo visits the tomb of Charles the Great, awaiting the results of the election for the new Holy Roman Emperor. Nearby, Ernani, Silva and others plan a conspiracy against the King. At the sounding of the horns, the voters enter the catacombs preceded by their pages. Don Carlos is victorious in the election. He sentences the conspirators to death. Ernani wishes to die with his compatriots but Elvira begs for mercy. Noble minded, the newly elected Emperor shows mercy and allows Ernani to marry Elvira.
Ernani, now officially recognised as Aragon’s Don Giovanni, and Elvira celebrate their wedding ceremony at the castle in Zaragoza. A disguised man moves among the revelers. As the newlyweds head to their room, Silva begins to blow a horn. Prayer and despair will not help – an oath cannot be broken. Ernani stabs himself, and Silva enjoys the sweet taste of revenge.