Synopsis

The action is based on the historical events of the Roman civil war of 48–47 BC. Julius Caesar has defeated his rival Pompey and pursued him to Alexandria, capital of Egypt. The kingdom is ruled jointly by Cleopatra and her younger brother Ptolemy (Tolomeo), the last of the dynasty established in Egypt after its conquest by Alexander the Great. Pompey has appealed to Tolomeo for arms and refuge.

Cesare enters Alexandria with his general Curio and his army to be met by Cornelia and Sesto, the wife and son of Pompey, who have come to sue for peace. Cesare agrees to embrace his enemy, but at that moment Tolomeo’s general Achilla arrives with a greeting and gift from his king: Pompey’s severed head. Disgusted Cesare sends Achilla back with an angry message for Tolomeo and a threatening promise that he will meet with the king at his palace before nightfall. Cornelia laments her loss and Sesto swears to avenge his dead father. In the palace at Alexandria, Cleopatra plots to take sole possession of the throne. When she learns of Tolomeo’s betrayal of Pompey from his servant Nireno, she resolves to visit Cesare’s camp and win his favour and aid. She and Tolomeo bicker before she steals away. Achilla tells Tolomeo of Cesare’s angry reception of his gift and offers to accomplish his murder if Tolomeo grants him Cornelia as a reward. Tolomeo fears the growing strength of Rome under the leadership of Cesare and agrees. At the camp, Cesare presides over Pompey’s funeral rites. In disguise, Cleopatra presents herself to Cesare as Lidia, a handmaiden in the palace, but one of noble birth, robbed of her birthright by Tolomeo. Captivated, Cesare promises to help her. Cleopatra and Nireno watch as Cornelia pays her last respects to her dead husband. Cornelia and Sesto plan to kill Tolomeo. Cleopatra comes forward and, though still disguised as Lidia, pledges the support of the Queen of Egypt, offering them the services of Nireno as a guide into the palace. Cesare meets with Tolomeo in an interview of frosty diplomacy. Nevertheless, he cautiously accepts the king’s invitation of hospitality. Cornelia and Sesto confront Tolomeo. He is struck by Cornelia’s beauty, but when Sesto challenges him to combat, he orders their imprisonment. Achilla offers Cornelia her freedom in return for her favours, but she angrily refuses. She and Sesto bid each other a sad farewell before the guards separate them.

In the palace, with Nireno’s help Cleopatra has arranged an entertainment calculated to ensnare further the interest of Cesare. Lured by Nireno, he duly arrives and is enchanted by her song. Nireno assures him that the supposed Lidia is deeply attracted and will wait for him later that night in her apartment. Cornelia, now Tolomeo’s prisoner, laments her fate. She repulses Achilla once more, only to be met by the advances of Tolomeo himself. She resolves to take her own life, but is saved by Sesto who has escaped with the aid of Nireno, who also brings the news that Tolomeo has commanded she become one of his concubines. He will help to smuggle Sesto into the harem as well, where, unguarded, the king will be at his most vulnerable. In her apartment, Cleopatra waits for Cesare, pretending to be asleep when he enters. The lovers’ tryst is interrupted by Curio, who has overheard Achilla’s assassin searching the palace for Cesare. Cleopatra reveals her true identity to Cesare and begs him to fly to safety. Cesare refuses and goes to meet his enemy. Cleopatra prays to the gods to preserve him and the love she now truly feels for him.

Tolomeo, secure in his harem, lays aside his arms. He throws a white veil to Cornelia in token that she is to be his that night. Sesto steals in and tries to use Tolomeo’s sword to kill him but is disarmed by Achilla. He summons the king to war; Cesare is believed to have plunged to his death in the harbour during the previous night’s assault, but Cleopatra has fled to the Roman camp and has there mustered an army to march on the palace. Tolomeo prepares to lead his troops, but refuses Achilla the promised reward for Cesare’s death; Cornelia is to be his own prize. A furious Achilla decides to switch his allegiance to Cleopatra. In the ensuing battle, Tolomeo’s troops are victorious and Cleopatra is taken prisoner. Her brother promises to take a terrible revenge but she faces death with courage. Cesare, though, is not dead; the sea has cast him up onto the shore. Far from his armies, he prays to the breezes for help. Sesto and Nireno stumble across the wounded Achilla dying on the beach. Overheard by Cesare, he gives Sesto a seal, the sight of which will give the bearer authority to command his troops. As Achilla dies, Cesare takes the seal from Sesto and goes to assemble a force to storm the palace. Sesto finds new hope. Revenge will soon be his. In prison, Cleopatra has prepared to take her own life. Cesare breaks in with his troops and rescues her. He sends her to the port to rally her armies and leaves to wage war on Tolomeo. Cleopatra rejoices. Believing himself to be victorious, Tolomeo sees no obstacle to his pursuit of Cornelia, but Sesto at last seizes his chance and kills him. The battle has been won and Cesare crowns Cleopatra as sole Queen of Egypt. She declares her allegiance to the Roman Empire. The lovers sing and all welcome the arrival of peace.