In 48 B.C. Julius Caesar (Sir Rex Harrison) pursues Pompey from Pharsalia to Egypt. Pharaoh Ptolemy XIII (Richard O'Sullivan) now supreme ruler after deposing his older sister Cleopatra VII (Dame Elizabeth Taylor) attempts to gain favor with Caesar by presenting the conquerer with the head of Pompey borne by his governors Pothinus (Grégoire Aslan) and Achillas (John Doucette). To win Caesar's support from her brother Cleopatra hides herself in a rug which Apollodorus (Cesare Danova) her servant presents to Caesar. The Roman is immediately infatuated. Banishing Ptolemy he declares Cleopatra Egypt's sole ruler and takes her as his mistress. A son Caesarion (Loris Loddi) is born of their union. Caesar however must return to Italy. Although he is briefly reunited with Cleopatra during a magnificent reception for the Queen in Rome Caesar is assassinated shortly thereafter and Cleopatra returns to Egypt. When Mark Antony (Richard Burton) Caesar's protégé beholds Cleopatra aboard her elaborate barge at Tarsus some years later he is smitten and becomes both her lover and military ally. Their liaison notwithstanding Antony to consolidate his position in Rome marries Octavia (Jean Marsh) sister of the ambitious Octavian (Roddy McDowall). The marriage satisfies no one. Cleopatra is infuriated and Antony tiring of his Roman wife returns to Egypt. There he flaunts his liaison by marrying Cleopatra in a public ceremony. Sensing Antony's weakness Octavian attacks and defeats his forces at Actium. Alarmed Cleopatra withdraws her fleet and seeks refuge in her tomb.