Characters

Cleofide, an Indian Queen in love with Poros.
Poros, King of another part of India, who jealously loves Cleofide, but who during the opera pretends part of the time to be his Commanding General Gandartes and part of the time Duke Hasbytes.
Eryxene, sister of Poros, betrothed to Gandartes, but secretly in love with Alexander and the object of affection of Alexander's Commanding General, Timagenes.
Alexander, King of Macedonia, currently invading India.
Gandartes, Commanding General of Poros' armies, who, on occasion, pretends to be Poros.
Timagenes, Commanding General of Alexander's armies, who, frustated in love, colludes with the enemy.

The opera is set in India, in various locations on and near the banks of the Hydaspes River.

Act 1

The opening scene, set on the Hydaspes river bank, shows the army of King Poros fleeing after being vanquished by the troops of Alexander the Great. Poros intends to kill himself after this humiliation, but is prevented from doing so by Queen Cleofide, a ruler from another part of India. Although Poros and Cleofide are in love, Poros suspects that she has been untrue to him and has become Alexander's mistress. When Alexander approaches, however, Poros pretends to be someone else, his Commanding General, Gandartes, and makes quite an impression on Alexander. When the false Gandartes leaves the scene, Alexander's own Commanding General, Timagenes offers him by way of tribute the bound and chained sister of Poros, Eryxene. Eryxene also happens to be the betrothed of the real Gandartes, but this does not prevent her from falling secretly in love with Alexander, who rather than take advantage of her, has her released. Alexander's Commanding General, Timagenes, however, has fallen in love with Eryxene, and in order to pursue his interest, quietly changes sides, secretly encouraging Alexander's troops to mutiny and ally themselves with Poros. Scene two is set in a palm grove, where Cleofide tries to assure Poros that her friendship with Alexander was no more than that, and intended to save India. Eryxene, having been released by her captors, returns and so extols Alexander that Cleofide rushes off to offer him her lands, much to the consternation of Poros. Gandartes, who has also happened on the scene, is likewise disturbed by Eryxene's new found passion and by her view that she can no longer be bound romantically by the past. Scene three takes us back to the river bank, where, after much emotional and tactical manouvering, on the part of the protagonists, many of them in disguise, Alexander informs Cleofide, that although he understands that she loves him and is willing to sacrifice so much, he can only be her friend and protector. This assertion, made in the presence of the ever jealous Poros, now disguised as Duke Hasbytes, convinces him that whatever Cleofide may say, she will in the end, remain faithful to him.

Act 2

The action starts in the royal chambers of Poros, where a discussion is taking place about how best to prevent Alexander from crossing the Hydaspus River and further extend his conquest of India. In the meantime, in pursuit of this, Alexander has had a bridge built across the river and Cleofide has come out in his support. Poros then starts his counter offensive, destroying the bridge, while his rear guard, led by Gandartes saves itself by jumping from the bridge into the river. Following this turn of events, Cleofide and Poros are brought together again, and after a raging argument during which Cleofide threatens to drown herself, decide to marry. However, feeling surrounded by enemies and the prospect of a hopeless future, they conclude that suicide may be the best answer. That this does not happen may best be understood by the fact that another series of misunderstandings and misrepresentations takes place and the scene ends with Poros being set free by Alexander's General, Timagenes, and Cleofide being blamed for the debacle that has befallen Alexander's army. The concluding scene from Act 2 is set in Cleofide's palace, where Alexander decides to save her from his army's retribution by proposing marriage. This proposal is overheard by Gandartes, who, disguised as Poros, offers his own life in exchange for that of Cleofide. Alexander is so impressed by this response, that although he we suspect he cannot really be sure who is who from the enemy side, with the exception of Cleofide, he forgives them all. To Cleofide, however, uncertainty remains, and when news is brought to her by Eryxene that Poros drowned after falling into the river, another case of mistaken identity as it will turn out to be, the act ends with her in despair.

Act 3 ...

is set in a colonnade in the palace gardens. The action opens with Eryxene being told that her brother Poros is not dead after all, but Cleofide, believing otherwise, has already agreed to marry Alexander for the sole purpose of bringing the fighting to an end. Eryxene, in her ignorance, sees this as a further sign of Cleofide's infidelity. What she does not know is that as soon as the marriage ritual starts, Cleofide intends to confess to Alexander that she is already married to Poros, but now that Poros is dead, she must, according to Indian custom, follow her late husband in death. Meanwhile, the role Timagenes has played in siding with the Indian army has come to light, but Alexander, in his infinite wisdom spares him. The final scene in the opera resolves the situation for everyone concerned. It turns out that Poros did not drown and is alive after all. And so, after weighing everything up, Alexander forgives everybody, granting both Poros and Cleofide their freedom and their lands. He also rewards Gandartes, whose true identity is now known by handing over to him some of the lands he has already conquered in India. Poros in turn rewards Gandartes with the hand of his sister Eryxene.