The mourning period following Emperor Vespasian's death has concluded, and his son, Titus, is poised to ascend the throne. Whispers abound that Titus will wed Bérénice, the queen of Palestine, whom he has loved for a long time. Meanwhile, Antiochus, both a war companion to Titus and a devoted friend to Bérénice, harbors unrequited love for her.

Antiochus's Dilemma

Antiochus, clinging to the hope that Titus might not marry Bérénice after all, plans to visit her one final time before departing Rome. He instructs his confidant, Arsace, to ready everything for his journey. Arsace is taken aback by Antiochus's decision to leave, especially now, when Titus is on the brink of great power, likely desiring his close friend's presence.

Bérénice's Hopes

Bérénice is confident that the rumors of her impending marriage to Titus will soon be confirmed. When Antiochus arrives to bid farewell, she harshly chastises him for confessing his love at such a moment. She expresses disappointment, having valued their friendship, and hoped he would remain to witness her anticipated joy.

Titus's Inner Conflict

Titus grapples with the reality that his love for Bérénice poses a challenge for the Roman Empire's stability. Consulting his trusted advisor Paulin, he learns that while the court might condone his decision, the Roman populace would never accept Bérénice as empress. Despite this, Titus desperately clings to the hope that he could marry her without inciting public outrage. He instructs Antiochus to escort Bérénice back to her homeland.

Mistaken Understandings

When Bérénice arrives, filled with love and joy, believing her marriage to Titus imminent, the emperor struggles to convey the truth. Unable to speak plainly, he blames his father's death for the constraints on him. Misinterpreting his words, Bérénice passionately declares her love, asserting she will mourn his absence more than he would his father's death. Titus, overwhelmed, cannot bring himself to tell her she cannot be empress.

A Moment of Doubt

Left with her confidante Phénice, Bérénice is troubled by Titus's evasive behavior. Remembering that Titus is meeting with Antiochus, she convinces herself that he is merely jealous, thus affirming his love for her, and reassures herself that things will soon be resolved.

Antiochus's Unwanted Role

When Antiochus arrives, Titus implores him to speak to Bérénice on his behalf, explaining that duty forces him to forsake their love. Alone with Arsace, Antiochus is torn between hope and sorrow—hope for himself and sorrow for his friend. Despite his hesitation, Bérénice persuades him to disclose Titus's decision. Unwilling to believe him, she insists on confronting Titus, threatening to end her own life in a tense encounter. Paulin struggles to prevent Titus from pursuing her as she departs, while Antiochus urgently pleads with Titus to save her life.

The Final Confrontation

As Titus meets with the senate, he asks Antiochus to assure Bérénice of his love. Arsace interrupts with news that Bérénice, preparing to leave Rome, has penned a letter to Titus. In distress, Antiochus announces his intent to end his life and leaves. Bérénice, emerging from her chambers, encounters Titus and informs him of her imminent departure. Titus professes his deep love for her, pleading for mercy, asking her to love him less when he commands her to go.

A Letter's Revelation

Titus finds Bérénice's letter, declaring her intention to die rather than live without him. In agony, he declares his love is so profound he would abandon his empire for her, despite knowing it would bring her shame. When she collapses, he threatens to take his own life if she does not promise to live. Antiochus arrives to witness the depth of his friend's weakness for love, confessing his own intention to commit suicide before Titus called him back.

Resolution and Departure

Moved by the heartache surrounding them, Bérénice accepts Titus's difficult choice. As she departs, she urges Antiochus to follow their example of selflessness. The three part ways, resigned to their separate fates.