Background

Tamerlano and his army have swept west from central Asia to the coast of Asia Minor, modern day Turkey; most recently he has conquered the Ottoman realm and taken captive the king, Bajazet, and his daughter, Asteria.

Andronico, a fugitive Byzantine prince, has allied himself with Tamerlano; he takes special care of Bajazet, and loves (and is loved by) Asteria. From Tamerlano Andronico learns the art of war, and from Andronico Tamerlano absorbs statecraft. Tamerlano is negotiating with Byzantium for Andronico’s return to power there as a client prince; he has also arranged a marriage for himself with Irene, the princess of the neighbouring Greek Pontic kingdom of Trebizond.

Act I

Andronico released the defeated king Bajazet from close confinement. At first, pleased, Bajazet recoils when he understands that this mercy has been extended by Tamerlano. Above all else, Bajazet and his daughter hate their conqueror. Bajazet tries to kill himself, but relents when Andronico reminds him of his vulnerable daughter.

Tamerlano has news for Andronico: he will restore him to power in Byzantium, and Tamerlano himself will placate his defeated foe by marrying his daughter Asteria. When Andronico raises the problem of Irene, whose arrival is imminent, Tamerlano happily decides to bestow her on Andronico, and he requires his friend to intercede for him with Bajazet and Asteria..

Andronico is caught between his loyalty to Tamerlano and his love for Asteria, and he prays that she will trust his heart, though his words may seem to betray her.

Asteria has heard of Andronico’s good fortune – and she resolves to harden her heart against him. Predictably, her father rejects Tamerlano’s offer of marriage on her behalf – but she herself will not commit herself, preoccupied as she is with her father’s safety and her lover’s assumed treachery.

When Irene arrives, she meets Andronico and shows her indignation at the idea of giving up Tamerlano. Andronico persuades her disguise herself as a companion to Irene, and wait to play her trump cards at the right moment. Even this slender plan makes Andronico hopeful of saving Bajazet, being true to Asteria, and not betraying Tamerlano.

Act II

Tamerlano thanks the mortified Andronico for his help in winning over Asteria, and indulges in some playful anticipation of love as a kind of “happy warfare”.

Andronico confronts Asteria, assuring her of his love – though close to confiding in him, she instead insults him (in order to protect hi and her plan), and decides to accept Tamerlano’s proposal. Andronico presents Irene (in disguise) to Tamerlano; she makes clear Irene’s rights but Tamerlano dismisses her.

The embittered Andronico admits to Bajazet that Asteria has chosen Tamerlano.

As Asteria accepts Tamerlano’s invitation to mount his throne (formerly Bajazet’s!) together, her father stops her. The conqueror orders his captive to prostrate himself, and Bajazet is contented to do so: he blocks his own daughter’s path to the throne, until kicked out of the way by Tamerlano. As all (Bajazet, Andronico and the hopeless Irene) watch Asteria join Tamerlano, Bajazet throws himself at her and begs her to kill her own father so he cannot witness her shame. Asteria’s resolve softens, and disgusted Tamerlano orders he to go back to captivity. She reveals to all the dagger with which she had planned to stab Tamerlano in their wedding night. Enraged, Tamerlano menaces both father and daughter – but cannot make himself kill the girl he now loves.

Asteria is vindicated by her planned murder. Bajazet reclaims her as his daughter, Andronico begs forgiveness for doubting her, and Irene pledges friendship. Alone, the heroine expresses her longing for light and life.

Act III

Bajazet and Asteria are imprisoned. As ever, he thirsts for a death that is not at the hand of Tamerlano. With his daughter he shares the small amount of poison that he has acquired – and he pledges to die himself once he is assured that she has the means to take her own life if assaulted by Tamerlano.

Tamerlano’s desire for Asteria is still keener, and he confesses it to her in front of Andronico. Andronico this time defies Tamerlano, and names his own love, which Asteria returns. Betrayed by his ally and scorned by the woman he loves, Tamerlano is maddened and violent. Asteria and Andronico recognise that their lives and their love will be short, but they join hands.

Tamerlano requires Asteria to abase herself before him by serving him wine on her knees. To humiliate her father and lover, they are forces to witness her degradation. Asteria secretly poisons the wine, but just as he is about to drink Tamerlano’s life is saved by Irene, who now reveals herself. Asteria begs him to drink, but Tamerlano orders her to offer the poisoned drink either to her father or her lover. In agony, Asteria goes to drink it herself, but Andronico dashes it from her hands. Still obsessed with Asteria, Tamerano sentences her to serve as the sex slave of his slaves.

Regretting the squandered poison, Bajazet has a furious burst of energy, in which he threatens Tamerlano with all the furies of hell. Bajazet then manages to consume the residue of the poison. Just as Tamerlano agrees to marry Irene after all, having purged himself of love for Asteria, an ecstatic, poisoned Bajazet hurls himself at Tamerlano, and terrifies the superstitious conqueror. He takes leave of his helpless daughter, who begs him to kill her. All witness his death, and all are changed by it.

Tamerlano, weakened, calls for hatred to be put aside. He offers to give Byzantium to shattered Andronico. In sombre fashion, Tamerlano, Andronico and Irene call out for light.