The Egyptian god Ra addresses the play’s audience directly, belittling them for their ignorance and insulting contemporary (mid-Victorian) British society. He also establishes the origins of Julius Caesar’s rivalry with Pompey, explaining that the gods favored Caesar, who lived boldly and had an affinity for progress and exploration. Ra recounts how Julius Caesar defeated Pompey at the Battle of Pharsalus and chased him to Egypt, where he was ultimately assassinated by Lucius Septimius in 48 B.C.E.
The action shifts to Cleopatra’s palace in Syria, where she has been banished by her brother Ptolemy, with whom she is fighting for control of Egypt. A wounded Egyptian soldier named Bel Affris staggers through the gate to warn the Egyptians that Julius Caesar’s powerful Roman army is on its way to conquer Egypt and will reach them soon. A Nubian sentinel runs inside the palace to warn everyone of the advancing army. Cleopatra’s chief nurse, Ftatateeta, emerges from the palace and informs the guards that Cleopatra, who is terrified of the Romans, has run away.
Cleopatra is sound asleep between the paws of a Sphinx. Julius Caesar approaches and praises the sphinx, failing to notice the young girl sleeping between its paws. Caesar’s voice awakens Cleopatra. When she calls out to him, Caesar initially believes the sphinx is talking to him. He believes he’s either dreaming or gone mad, but realizes his error once Cleopatra emerges from her hiding place and introduces herself. Cleopatra informs Caesar that she’s run away. Unaware of her new acquaintance’s identity, Cleopatra shares with Caesar her childish fears about the Romans and their ruthless leader, Julius Caesar. Caesar convinces Cleopatra to return to the palace at Alexandria and face her Roman conquerors. He promises to teach her how to be brave and act like a Queen. Cleopatra reluctantly agrees and escorts Caesar to the palace at Alexandria. The Roman guards arrive and hail Caesar, prompting Cleopatra to realize that she’s been with the supposedly ruthless Caesar all along. She sobs with relief and collapses into Caesar’s arms.
The scene shifts to the royal palace in Alexandria, where King Ptolemy’s court is in session. Pothinus, Ptolemy’s guardian, impatiently guides Ptolemy through a speech about resisting the attempts of Caesar—a foreigner—to meddle in Egypt’s affairs. Caesar arrives and demands repayment for funds Ptolemy’s father borrowed from Rome. If Egypt cannot produce the funds, Caesar will settle Ptolemy and Cleopatra’s feud over the Egyptian throne by letting them rule jointly. Caesar’s offer enrages Cleopatra, who hates her brother. Pothinus and the other adults in Ptolemy’s close circle also reject Caesar’s proposition. The Egyptians threaten to retaliate with military intervention.. Although the combined forces loyal to Egypt outnumber Caesar’s army, Caesar remains unconcerned.
Caesar orders Rufio, one of his lead officers, to take control of the palace and the lighthouse on Pharos, an island in Alexandria’s harbor. Rufio departs to put Caesar’s plans into action. Caesar remains behind to strategize further, though he’s distracted by Cleopatra’s childish vies for attention. Theodotus, Ptolemy’s tutor, enters the hall in a panic to announce that the Library of Alexandria is on fire.
Ftatateeta and a Sicilian patrician named Apollodorus smuggle Cleopatra, whom the Romans are holding captive, out of the palace in a rolled up Persian carpet. Apollodorus boards a ship and delivers the carpet to the lighthouse on Pharos, where Caesar, Rufio, and Caesar’s treasurer, Britannus, are resting after the day’s battle. Cleopatra emerges from the carpet, surprising Caesar. Cleopatra is upset when she realizes that Caesar is too preoccupied with military strategizing to pay attention to her. Britannus announces that the Egyptians are headed toward the island. By now Apollodorus’s ship has sunk, leaving the group with no other option but to swim across the harbor to procure another ship.
Six months later, the Roman army has defeated the Egyptian army. Pothinus, now a prisoner of war, meets with Cleopatra. They argue over whether Ptolemy or Cleopatra will rule Egypt when Caesar returns to Rome. Pothinus realizes that he underestimated Cleopatra, who has matured considerably under Caesar’s guidance, and he resolves to turn Caesar against her. Later, Pothinus arrives on the palace rooftop, where Cleopatra is hosting a feast for Caesar and his men. He accuses Cleopatra of ingratiating herself with Caesar as a political ploy to gain control of Egypt once Caesar leaves. Cleopatra rejects Pothinus’s accusation, but Caesar takes no offense, reasoning that anybody in Cleopatra’s position would do the same. Pothinus’s attempt to slander her in front of Caesar enrages Cleopatra, so she secretly orders Ftatateeta to murder Pothinus.
The rooftop festivities continue. Cleopatra is delighted when Caesar suggests that he postpone his return to Rome to search for the source of the Nile and establish a new kingdom there. Their plans are interrupted by Pothinus’s agonized scream. A bloody Ftatateeta returns to the roof. Soon after, they can hear a riot forming outside the palace. Cleopatra feigns ignorance but eventually admits that she arranged for Pothinus’s murder as revenge. Caesar admonishes Cleopatra for destroying the peace. All hope seems lost until Caesar and his men learn that supporting Roman troops led by Mithridates of Pergamos have arrived to take on the Egyptian army. Caesar and his men leave to join the troops. Rufio realizes that it was Ftatateeta who killed Pothinus and murders her in retaliation. Cleopatra later discovers Ftatateeta’s body.
Caesar and the Roman army have now defeated the Egyptians. Ptolemy’s ship sank during battle and he drowned, leaving Cleopatra to rule Egypt in Caesar’s absence. A military pageant is in full force to bid farewell to Caesar, who is preparing to return to Rome. A crowd cheers as Caesar approaches the harbor. As Caesar prepares to board his ship, he appoints Rufio to be the Roman governor and Apollodorus to oversee Egypt’s art. Cleopatra approaches Caesar, dressed in mourning clothes. She accuses Rufio of the Ftatateeta’s murder and is shocked and enraged when Caesar defends Rufio’s actions as justified. Cleopatra initially sulks and refuses to say goodbye to Caesar, but she comes around once Caesar promises to send Mark Antony to Egypt to be her husband. Cleopatra weeps and waves as Caesar boards his ship and leaves for Rome.
