Giulio Cesare has chased his enemy Pompeo to Egypt, beyond the borders of the Roman Empire. Pompeo is defeated and his wife Cornelia begs Cesare to spare her husband. He is about to grant her plea, only to discover Pompeo murdered at the command of Tolomeo, who rules Egypt alongside his sister Cleopatra. The two siblings are locked in a struggle for absolute power. Sesto, son of Cornelia and Pompeo, swears to take revenge for his father’s death. On the other hand, Cleopatra successfully seduces Cesare hoping that he will support her as she tries to secure her power in Egypt.

Meanwhile, Tolomeo has ordered Cornelia to be sent to his harem. Cornelia plots with Sesto to murder Tolomeo by sneaking Sesto into the harem. However, this assassination attempt was not successful. Cleopatra again seduces Cesare at her palace. Cesare is deeply enchanted by her singing.

Cesare, who is thought to be dead, is ambushed by Tolomeo’s guards and escapes into the desert. He vows to either save both Cleopatra and Cornelia or die. Sesto murders Tolomeo while the victorious Cesare enters Alexandria. The battle has been won and Caesar crowns Cleopatra as the only ruler of Egypt. She declares her allegiance to the Roman Empire.