Prologue

The story takes place in Genoa in the middle of the 14th century. The Republic of Genoa is about to elect a doge. The nominee of the plebeian popular leaders Pietro and Paolo is Simon Boccanegra, who has successfully cleared the harbour of pirate ships. Boccanegra has so far rejected the position. However, his beloved Maria is being kept prisoner in the castle of her tyrannical father, Fiesco. Even though Maria has borne Boccanegra a baby girl, her aristocratic father opposes his relationship with his daughter, deeming him too lowly in station to marry her. For this reason, he has even separated the child from her mother. Pietro and his comrades succeed in getting Boccanegra to assume the post of governor after all: this way he cannot be denied Maria's hand in marriage.

In the square in front of the palace, Fiesco is mourning his dead daughter in loving sorrow and grief when he encounters Boccenegra, who believes that his victories in battle merit him the young noblewoman's hand. Fiesco, however, fears that Boccanegra is trying to also take control of the city away from him and swears revenge on him. Fiesco asks Boccanegra to bring him his illegitimate daughter, his own granddaughter, so that he can raise her in a manner befitting her rank. If Boccanegra complies, he will pardon him. Boccanegra, however, is unable to fulfil this request, as the girl has been abducted: she has vanished without a trace.

Left alone, Boccanegra summons up all his courage to enter the palace to see his beloved again. But instead of a joyous reunion, he finds the dead young woman laid out on a bier.

Meanwhile, the deliriously overjoyed people call out the name of the new doge: “Boccanegra”. Fiesco flees.

Act I

Twenty-five years later, while waiting for her beloved in the Grimaldi palace not far from Genoa, Amelia broods over a sorrowful memory: long ago she was abducted and brought to this wealthy home by a strange woman. She is interrupted by the arrival of Gabriel Adorno, the young patrician with whom she is in love. Amelia is afraid for him, because he has helped incite the revolt and therefore is now in danger.

An emissary arrives: it is Pietro announcing the arrival of the doge. He has come to ask to have the girl married to Paolo, a confidante of his. Gabriele sends for a monk, so that he can quickly give his blessing to the marriage to the girl.

The monk – who is really Fiesco – appears and reveals Amelia's secret: she was of low birth, and the childless Countess Grimaldi abducted her when she was a little child. Later on, shortly before she died, the countess made Amelia her heir. The monk gives his blessing to their union.

Boccanegra arrives with Paolo, but immediately sends him back when he receives news that the people are seething with discontent in Genoa.

The girl knows that Paolo only wants her for her wealth, so she tells Boccanegra her secret: she is not a Grimaldi by blood. The girl believes that her father is dead. Boccanegra feels a glimmer of hope and shows her a portrait of her mother. Before her death, Countess Grimaldi had shown the girl the same portrait of her real mother. Father and daughter are happily reunited. They swear to each other that they will keep their secret.

Boccanegra commands Paolo to withdraw his offer of marriage. Paolo assigns Pietro the task of abducting the girl.

The malcontents are getting ready to revolt against the doge. The people, however, turn against the rebels. Boccanegra calls for peace and is ready to make Paolo doge. Paolo, however, has pronounced a curse on the guilty and flees in horror.

Act II

Paolo decides that he must kill Boccanegra and mixes poison into his cup. He has Gabriele and Fiesco, who are imprisoned in the palace, brought before him and then offers Fiesco his freedom if he is willing to stab Boccanegra with a dagger. Fiesco, however, has nothing to say to the traitor. Paolo leads Gabriele to believe that the doge is keeping Amelia in the palace as his lover. Learning of this, Gabriele plots revenge against the doge. Just as he is lamenting her faithlessness and the loss of their love, in comes Amelia. Without revealing her secret, she tells Gabriele that her affection for the doge is holy and that Boccanegra is guilty of nothing. She assures Gabriele of her love. Upon hearing the doge's approaching footsteps, Amelia instructs Gabriele to hide. But even the girl is unable to dissuade him from his plan of killing Boccanegra.

Amelia reveals the name of her lover to her father. Since Gabriele has rebelled against him, he can show him no mercy either. The girl declares that if the doge has Gabriele killed, she will die along with her lover. After she has left, he drinks from the cup that Paolo has poisoned and immediately falls asleep. Gabriele emerges from his hiding place and is preparing to stab the sleeping doge when Amelia rushes in and manages to throw herself between the two men. Boccanegra awakens. Amelia is about to reveal her life's secret to her beloved, but the doge notices the dagger in the young man's hand and himself tells Gabriele that Amelia is his daughter. Dumbfounded, Gabriele feels that it would be a just punishment for the doge to kill him. But the doge is ready to die, if it means that there will be peace between the parties.

The crowd of rebels is approaching. Boccanegra asks Gabriele to convince the people to withdraw. Gabriele starts off, hoping that that the crowd will rejoice when the doge calls for peace. As a reward, the father promises his daughter to the youth, who rushes off to face the rebels.

Act III

A few hours later, the captain of the crossbowmen leads in Fiesco, who has been freed from prison. Then they bring in Paolo, clapped in fetters for having incited the rebellion that they have just quashed. Boccanegra sentences him to death, and he is led away by the executioner. Amelia and Gabriele are accompanied by a bridal procession. Fiesco emerges from his place of concealment, ready to wreak his revenge. Boccanagre admonishes him, reminding him that he once promised him peace if he handed over his daughter. Now he reveals that his daughter is none other than Amelia Grimaldi. The two men reconcile. Fiesco reveals that the doge's drink was poisoned by a traitor. Unafraid of death, Boccanegra embraces Fiesco one last time and reveals to Amelia that Fiesco is the father of her departed mother. Boccanegra bids farewell to his daughter. His final acts are to confer a blessing on his child and to install Gabriele as the next governor.

Time: The middle of the 14th century.
Place: In and around Genoa.

Prologue

(Act 1 in the 1857 original)
A piazza in front of the Fieschi palace

Paolo Albiani, a plebeian, tells his ally Pietro that in the forthcoming election of the Doge, his choice for the plebeian candidate is Simon Boccanegra. Boccanegra arrives and is persuaded to stand when Paolo hints that if Boccanegra becomes Doge, the aristocratic Jacopo Fiesco will surely allow him to wed his daughter Maria. When Boccanegra has gone, Paolo gossips about Boccanegra's love affair with Maria Fiesco – Boccanegra and Maria have had a child, and the furious Fiesco has locked his daughter away in his palace. Pietro rallies a crowd of citizens to support Boccanegra. After the crowd has dispersed, Fiesco comes out of his palace, stricken with grief; Maria has just died (Il lacerato spirito – "The tortured soul of a sad father"). He swears vengeance on Boccanegra for destroying his family. When he meets Boccanegra he does not inform him of Maria's death. Boccanegra offers reconciliation and Fiesco promises clemency only if Boccanegra lets him have his granddaughter. Boccanegra explains he cannot because the child, put in the care of a nurse, has vanished. He enters the palace and finds the body of his beloved just before crowds pour in, hailing him as the new Doge.

Act 1

(Act 2 in the 1857 original)
File:Figlia a tal nome io palpito - Simon Boccanegra.webm

Twenty-five years have passed. Historically the action has moved from 1339, the year of Simon's election in the prologue, forward to 1363, the year of the historical Simone Boccanegra's death – for acts 1, 2 and 3.
The Doge has exiled many of his political opponents and confiscated their property. Among them is Jacopo Fiesco, who has been living in the Grimaldi palace, using the name Andrea Grimaldi to avoid discovery and plotting with Boccanegra's enemies to overthrow the Doge. The Grimaldis have adopted an orphaned child of unknown parentage after discovering her in a convent (she is in fact Boccanegra's child, Maria – known as Amelia – named after her mother, and she is Fiesco's granddaughter). They called her Amelia, hoping that she would be the heir to their family's fortune, their sons having been exiled and their own baby daughter having died. Amelia is now a young woman.
Scene 1: A garden in the Grimaldi palace, before sunrise

Amelia is awaiting her lover, Gabriele Adorno (Aria:Come in quest'ora bruna – "How in the morning light / The sea and stars shine brightly"). She suspects him of plotting against the Doge and when he arrives she warns him of the dangers of political conspiracy. Word arrives that the Doge is coming. Amelia, fearing that the Doge will force her to marry Paolo, now his councilor, urges Adorno to ask her guardian Andrea (in reality, Fiesco) for permission for them to marry: Sì, sì dell'ara il giubilo / contrasti il fato avverso – "Yes, let the joy of marriage be set against unkind fate".

1857 original version: the duet ended with a cabaletta (set to the same words as the 1881 text) then "a coda and a battery of chords followed by applause."
Fiesco reveals to Adorno that Amelia is not a Grimaldi, but a foundling adopted by the family. When Adorno says that he does not care, Fiesco blesses the marriage. Boccanegra enters and tells Amelia that he has pardoned her exiled brothers. She tells him that she is in love, but not with Paolo, whom she refuses to marry. Boccanegra has no desire to force Amelia into a marriage against her will. She tells him that she was adopted and that she has one souvenir of her mother, a picture in a locket. The two compare Amelia's picture with Boccanegra's, and Boccanegra realizes that she is his long-lost daughter. Finally reunited, they are overcome with joy. Amelia goes into the palace. Soon after, Paolo arrives to find out if Amelia has accepted him. Boccanegra tells him that the marriage will not take place. Furious, Paolo arranges for Amelia to be kidnapped.

Scene 2: The council chamber

1881 revision: This entire scene was added by Verdi and Boito in place of the 1857 scene, which took place in a large square in Genoa.
The Doge encourages his councillors to make peace with Venice. He is interrupted by the sounds of a mob calling for blood. Paolo suspects that his kidnapping plot has failed. The Doge prevents anyone leaving the council chamber and orders the doors to be thrown open. A crowd bursts in, chasing Adorno. Adorno confesses to killing Lorenzino, a plebeian, who had kidnapped Amelia, claiming to have done so at the order of a high-ranking official. Adorno incorrectly guesses the official was Boccanegra and is about to attack him when Amelia rushes in and stops him (Aria: Nell'ora soave – "At that sweet hour which invites ecstasy / I was walking alone by the sea"). She describes her abduction and escape. Before she is able to identify her kidnapper, fighting breaks out once more. Boccanegra establishes order and has Adorno arrested for the night (Aria: Plebe! Patrizi! Popolo! – "Plebeians! Patricians! Inheritors / Of a fierce history"). He orders the crowd to make peace and they praise his mercy. Realizing that Paolo is responsible for the kidnapping, Boccanegra places him in charge of finding the culprit. He then makes everyone, including Paolo, utter a curse on the kidnapper.

Act 2

(Act 3 in the 1857 original)
The Doge's apartments

1881 revised version: There are some small adjustments in this act which include expanding Paolo's opening aria, thus giving him greater stature in the work: Me stesso ho maledetto! / "I have cursed myself", the wording of which was originally: O doge ingrato ... ch'io rinunci Amelia e i suoi tesori? / "O ungrateful Doge! ... Must I give up Amelia and her charms".
Paolo has imprisoned Fiesco. Determined to kill Boccanegra, Paolo pours a slow-acting poison into the Doge's water, and then tries to convince Fiesco to murder Boccanegra in return for his freedom. Fiesco refuses. Paolo next suggests to Adorno that Amelia is the Doge's mistress, hoping Adorno will murder Boccanegra in a jealous rage. Adorno is furious (Aria: Sento avvampar nell'anima – "I feel a furious jealousy / Setting my soul on fire"). Amelia enters the Doge's apartments, seeming to confirm Adorno's suspicions, and he angrily accuses her of infidelity. She claims only to love him, but cannot reveal her secret – that Boccanegra is her father – because Adorno's family were killed by the Doge. Adorno hides as Boccanegra is heard approaching. Amelia confesses to Boccanegra that she is in love with his enemy Adorno. Boccanegra is angry, but tells his daughter that if the young nobleman changes his ways, he may pardon him. He asks Amelia to leave, and then takes a drink of the poisoned water, which Paolo has placed on the table. He falls asleep. Adorno emerges and is about to kill Boccanegra, when Amelia returns in time to stop him. Boccanegra wakes and reveals to Adorno that Amelia is his daughter. Adorno begs for Amelia's forgiveness (Trio: Perdon, Amelia ... Indomito – "Forgive me, Amelia ... A wild, / Jealous love was mine"). Noises of fighting are heard – Paolo has stirred up a revolution against the Doge. Adorno promises to fight for Boccanegra, who vows that Adorno shall marry Amelia if he can crush the rebels.

Act 3
(Act 4 in the 1857 original)
1857 original version: Act 4 opened with a double male voice chorus, and a confused dialogue involving references to details in the original play.
Inside the Doge's palace

The uprising against the Doge has been put down. Paolo has been condemned to death for fighting with the rebels against the Doge. Fiesco is released from prison by the Doge's men. On his way to the scaffold, Paolo boasts to Fiesco that he has poisoned Boccanegra. Fiesco is deeply shocked. He confronts Boccanegra, who is now dying from Paolo's poison. Boccanegra recognizes his old enemy and tells Fiesco that Amelia is his granddaughter. Fiesco feels great remorse and tells Boccanegra about the poison. Adorno and Amelia, newly married, arrive to find the two men reconciled. Boccanegra tells Amelia that Fiesco is her grandfather and, before he dies, names Adorno his successor. The crowd mourns the death of the Doge.