At the Palace of Whitehall in London the Court are celebrating. The Duke of Anjou brother to the King of France has sought Queen Elizabeths hand in marriage and the glorious alliance of the two kingdoms is eagerly anticipated. Elizabeth enters still undecided as to whether she will accept the French proposal. For a long time her heart has belonged to her favorite Robert Dudley Earl of Leicester but recently she has sensed that his love for her is waning. Talbot Earl of Shrewsbury and Mary Stuarts custodian for many years takes the opportunity to petition the Queen for her cousins release. Cecil Elizabeths Secretary of State argues that Mary presents a constant threat to the stability of England while she remains alive. Elizabeth refuses to be drawn into the subject of her cousin but privately fears that the Queen of Scots has stolen the love of Leicester from her. In the past Leicester has been a suitor for Marys hand and was dazzled by the young Queens beauty when he first met her long ago in France. Leicester arrives and Elizabeth gives him a ring to convey to the French Ambassador in equivocal acceptance of Anjous proposal. His indifferent response fuels her suspicions and she leaves attended by the Court. Alone with Leicester Talbot secretly hands him a letter and a miniature sent by Mary. Enmeshed in the plots of the English Catholics against Elizabeth Marys life now hangs in the balance. Enraptured by the portrait Leicester vows to give his aid and support to Talbots plans for Marys liberation. As Talbot leaves Elizabeth returns alone. Suspicious of Talbot she demands to see the letter in Leicesters hands. Mary has written to beg Elizabeth for an audience and despite herself tears spring to Elizabeths eyes. Seizing his advantage Leicester presses the Queen to agree to ride out near Marys prison on a hunt and under this pretext engineer a meeting between the two queens. Although mistrustful Elizabeth agrees to her favorites request.
Unexpectedly allowed by Talbot to walk freely in the park outside her prison of Fotheringhay Castle Mary rejoices running far ahead of her lady-in-waiting Hannah Kennedy. Her thoughts turn to times of happiness and liberty in France. The horns of the royal hunt are suddenly heard in the distance. The approaching huntsmen cry out Elizabeths name and Mary is struck with fear at the prospect of finally setting eyes on her cousin. Leicester has ridden ahead of the hunt to prepare Mary for the meeting. He urges her to humble herself before Elizabeth and move the Queen to pity. Pledging his love and loyalty he promises Mary that she may yet be free. He hastens to greet Elizabeth as she arrives with the hunting party. She is agitated and suspicious and Leicesters solicitude for Marys cause rouses her jealousy. Talbot leads Mary forward and the two queens stare into each others eyes for the first time. Mary masters her pride and shows deference before Elizabeth but her cousin remains aloof and insulting. She accuses Mary of licentiousness murder and treason. The tender words with which Leicester tries to calm Mary serve only to increase Elizabeths anger. Insulted beyond endurance Mary turns on Elizabeth. She denounces her as the illegitimate offspring of a whore one whos foot sullies and dishonors the throne of England. Elizabeth orders the guards to seize Mary and drag her back to her prison.
Time has passed and Mary has remained incarcerated at Fotheringhay under ever harsher conditions. The marriage to Anjou is now a faded dream for Elizabeth. Cecil has procured evidence that implicates Mary in a Catholic plot to assassinate Elizabeth and a warrant for her death lies on the Queens desk at the Palace of Whitehall. But Elizabeth is racked with anxiety and fear. If she signs it she sends an anointed monarch to the scaffold and makes an enemy of all Catholic Europe. Cecil urges her to be strong her own life could be at stake and all England will applaud her and defend her if need be. Elizabeths indecision ends when Leicester enters the chamber. Quickly and indifferently she signs the warrant and hands it to Cecil. Appalled Leicester pleads with her to rescind the order and show mercy. Elizabeth commands him to be present as witness to the execution. Leicester tells her that she has sent a sister to her death and leaves.
In her room at Fotheringhay Mary rails bitterly against her fortune. Suddenly Cecil and Talbot enter to tell her that she must die in the morning. Cecil offers her the services of a Protestant minister in her final hours. Angrily she refuses and commands him to leave but asks Talbot to stay. He tells her that Leicester will be present when she dies and tries to comfort her. But Mary is tormented by the ghosts of her past and longs to make the confession to God that Cecil has denied her by refusing the ministrations of a Catholic priest. Her heart is heavy with the bloody memories of her short reign in Scotland and the deaths of her beloved favorite David Rizzio and her husband Darnley. Gently Talbot urges her to confess to him. She agrees and begins to unburden her conscience. Finally she confesses her unwitting acquiescence in the fatal plot of the English Catholic Sir Anthony Babington to assassinate Elizabeth. She and Talbot pray together for Gods absolution and Mary calmly prepares for death.
Early next morning Marys faithful servants gather weeping outside the great hall of Fotheringhay where Mary will be beheaded. The Queen enters. She asks them not to shed tears as death comes to liberate her. She gives Hannah a silken handkerchief to bind her eyes when the moment comes and leads the household in a fervent prayer. The shot of a cannon on the ramparts above signals that the time of execution is near and Cecil arrives with guards to conduct Mary into the hall. Elizabeth has sent word that all requests should be granted her in her final moments and Mary asks that Hannah may accompany her to the scaffold. She tells Cecil that she forgives her cousin and prays that her blood will wash away all memory of hatred between them. Leicester suddenly appears distraught as more shots of the cannon indicate the time has come. Mary calms him. She is content that she will die with him close at hand. She prays that England may be spared the vengeful wrath of God. Dressed in red the color of Catholic martyrdom she ascends the scaffold.
Premiere took place December 26 1830 in Milan in the theater Carcano.