Setting: Genoa, Italy, prologue is 1918 with Act I in 1943 just before the downfall of the Italian Fascist leadership
PROLOGUE – in a piazza
Simon Boccanegra, a former pirate, has been nominated for the position of Doge by party leaders Paolo and Pietro. Boccanegra hopes this will allow him to marry Maria (the daughter of Jacopo Fiesco). Maria has been imprisoned by her father for having an illegitimate daughter (also named Maria) with Boccanegra. During this time, she has died leaving Fiesco in mourning (Il lacerato spirito). Unaware of Maria’s death, Boccanegra begs forgiveness from Fiesco. Fiesco agrees with the condition that he is allowed to raise his granddaughter but Boccanegra tells him that the child has disappeared. Boccanegra is elected and as he enters the palace, he discovers Maria’s body.
Backstory; twenty-five years have passed and Boccanegra has removed many of his political opponents and seized their property. The exiled Fiesco lives under the assumed name Andrea and is the guardian of Amelia Grimaldi, supposedly the daughter of Count Grimaldi but in reality she is Maria Boccanegra. She had been raised by an old woman while Boccanegra was at sea. Upon his return, he found the old woman had died and the child was gone. She was found by Count Grimaldi and Fiesco became her guardian when Grimaldi was exiled. Neither Boccanegra nor Fiesco know her true identity.
Scene 1 – the gardens of the Grimaldi palace near the sea, 25 years later
Now a grown woman, Amelia awaits her lover Gabriele Adorno and reminisces about her childhood by the sea (Come in quest’ora bruna). Gabriele arrives and Amelia is concerned for his safety as he is plotting against Boccanegra. She is also concerned that Boccanegra wants her to marry Paolo. Gabriele leaves to ask Andrea/Fiesco for his blessing giving Fiesco the opportunity to tell him about Amelia’s adoption. Fiesco gives Gabriele his blessing on his relationship with Amelia. Boccanegra arrives with Grimaldi’s pardon in hand and discovers that Amelia is not Grimaldi’s biological daughter. She shows him a locket with a portrait of her mother and Boccanegra realizes this is his long lost daughter. Father and daughter have a lovely reunion and Boccanegra tells Paolo that he cannot marry Amelia, so Paolo plots with Pietro to kidnap her.
Scene 2 – the Council Chamber of the Doge’s Palace
During a Council meeting, shouting is heard from the street as Gabriele and Andrea/Fiesco are dragged into the chambers. Gabriele admits killing Lorenzino who tried to abduct Amelia and accuses Boccanegra of the kidnapping plot. Gabriele tries to stab Boccanegra but Amelia intervenes and describes her attempted abduction. Boccanegra pleads for peace and unity then turns to Paolo and urges him to curse the villain behind this plot, even though that means Paolo is cursing himself.
ACT II – the Doge’s chambers at night
Alone, Paolo decides he must get rid of Boccanegra and sends Pietro to bring Gabriele and Andrea/Fiesco from prison. Paolo pours poison into Boccanegra’s water pitcher and then tries to convince them to aid in the assassination but both refuse, until Paolo insinuates that Amelia is really the mistress of Boccanegra. Gabriele is furious even when Amelia arrives and tries to explain but Boccanegra enters before she can assuage Gabriele’s anger. Gabriele goes into hiding while Amelia reveals to Boccanegra that Gabriele is her lover and if he is not pardoned, she will die with him. Boccanegra dismisses her and considers her plea while drinking from the poisoned water jug. Gabriele returns, having not heard any of the previous conversation, and vows revenge on the man who killed his father. As he moves to stab Boccanegra, Amelia returns and stops him. Boccanegra tells Gabriele that he is Amelia’s father. Gabriele begs forgiveness as an angry mob is heard outside. Boccanegra urges Gabriele to join his friends in the rebellion but Gabriele promises to try to end the fighting. Boccanegra gives his blessing to Amelia and Gabriele.
ACT III – the great hall overlooking Genoa’s harbor
The rebellion has been crushed and Andrea/Fiesco has been released from prison. Paolo has been arrested and is being escorted to the scaffold while music from Amelia and Gabriele’s wedding is heard. Boccanegra enters the great hall, already suffering from the effects of the slow poison. Fiesco reveals his true identity and Boccanegra asks for forgiveness now that he has a short time to live and also reveals that Amelia is Fiesco’s granddaughter. Boccanegra appoints Gabriele as his successor before he dies. Fiesco addresses the celebrating crowd and tells them of Boccanegra’s death.