Julius Caesar, after having beaten Pompey at Pharsale in Greece, pursues him to Eygpt where he has taken refuge with Ptolemy XIV, who reigns over the valley of the Nile with his sister Cleopatra.

Act 1:
A PLAIN IN EYGPT
The curtain rises on Caesar’s arrival in Eygpt. Cornelia and Sextus, Ptolemy’s wife and son, come to ask for peace. They are interrupted by Achilla who brings, in the name of his master Ptolemy, gifts intended to win Caesar’s favour. Under the gifts is Pompey’s head. Caesar reacts indignantly to the practices of this barbaric sovereign. Cornelia is overcome with grief. Sextus swears to avenge his father.

THE ROYAL PALACE
Cleopatra is horrified to learn of Pompey’s death from the mouth of Nirenus, who, under cover of serving Ptolemy, is the trusty confident of the queen. Ptolemy appears and immediately they start to quarrel over power. Achilla appears sud- denly and reports on his discussions with Caesar. On hearing Ptolemy’s fury, he promises to kill Caesar on condition that he receives the hand of Cornelia in reward.

CAESAR’S CAMP
Cleopatra appears with Nirenus. She pretends to be Lydia, a young girl in Cleopatra’s suite. Captivated by her beauty, Caesar promises his help. Confident in her subterfuge, Cleopatra counts on her looks to triumph over her brother. Cornelia comes to commune with Pompey’s ashes. Sextus appears suddenly and prevents her from carrying out the vengeance that should by right be his. Cleopatra, still passing herself off as Lydia, and Nirenus offer to guide them to the tyrant. Alone, Cleopatra sings of her hope of seeing her plans accomplished.

A RECEPTION ROOM IN THE ROYAL PALACE
Julius Caesar and Ptolemy outdo each other in diplomacy but their courtesies do not hide a reciprocal disdain. Cornelia and Sextus appear, defying Ptolemy, who is not insensible to the spectacle of the enraged widow and has her arrested along with her son. He promises the widow to Achilla but secretly reserves her for himself. Achilla offers Cornelia her liberty in return for mar- riage but meets with refusal.

Act 2:
THE PLAY OF VIRTUE
Having prepared with Nirenus an allegorical play intended to captivate Caesar, Cleopatra appears to the sound of heavenly music in the role of Virtue surrounded by the nine Muses. An ecstatic Caesar prepares to follow Nirenus, who will lead him to Lydia’s apartments.

IN THE PALACE GARDENS
Cornelia is employed in humiliating tasks under the eye of Achilla. Ptolemy in turn tries to seduce Cornelia, who rebuffs his advances. Alone, Cornelia prepares to take her life by throwing herself into the lion pit. She is prevented from doing so by Sextus and Nirenus, who has received the order to take Cornelia to the harem. Nirenus offers to hide Sextus in the seraglio so that he may kill Ptolemy before he can violate his mother.

THE GARDEN OF DELIGHTS
The tender conversation between Cleopatra and Caesar is interrupted by Curio, who reveals to Caesar that a plot is being hatched against him. Cleopatra gives herself away and Caesar leaves to confront the conspirators. Alone, Cleopatra realises that she has become the victim of her own scheming; she is in love with Caesar and asks the gods to protect him.

THE HAREM
Ptolemy prepares to violate Cornelia. Sextus, who has entered unobserved, makes to seize the tyrant’s sword when Achilla appears and grabs it. The Egyptian affirms that Caesar has perished diving from a palace window into the port of Alexandria to escape the ambush. Cleopatra has taken the head of the Roman armies and battle is about to commence. Confident in victory, Ptolemy rejects Achilla’s demand for his due, the hand of Cornelia.

Act 3:
THE BATTLE
Achilla, betrayed by Ptolemy, decides to join Cleopatra. But the battle turns in the Egyptians’ favour and they capture the queen. Cleopatra weeps for Caesar whom she believes to be dead.

THE SHORE
Caesar has not perished. He has swum to the shore, exhausted and worried about the fate of his army and still more about that of Cleopatra. Sextus and Nirenus hear the confession of Achilla, who lies dying and who gives them a seal which will rally the troops with whom they will able to enter the palace secretly. Having revealed himself, Caesar claims the seal and hurries off to save Cleopatra.

CLEOPATRA’S PRISON
Cleopatra prepares to die. But the arms she hears are Caesar’s. He has come to free her before completing his victory over Ptolemy.

THE HAREM
Ptolemy prepares to ravish Cornelia. Sextus rushes upon him and kills him. Pompey’s widow begins to rediscover a taste for life.

THE PORT OF ALEXANDRIA
Sextus and Cornelia bring Ptolemy’s crown. Caesar hands it to Cleopatra, who acknowledges that she is his vassal. They declare their love. All celebrate the return of peace, while Caesar and Cleopatra take to the Nile heading for the pyramids.