After the assassination of Julius Caesar in 44 B.C., the Roman Republic was led by the Second Triumvirate, which consisted of Octavian (the adopted son of Julius Caesar), Mark Antony (the magister equitum of Caesar’s army), and Marcus Aemilius Lepidus (a political ally of Julius Caesar). After Lepidus was marginalized, Octavian and Mark Antony vied for supremacy. Mark Antony relocated to Alexandria, became Cleopatra’s lover and partner, and proclaimed Caesarion (Julius Caesar’s illegitimate son by Cleopatra) as Caesar’s true heir. After some hesitation, the Roman Senate threw its support behind Octavian. Antony, whose military power was in the eastern provinces, gathered his forces in Greece with plans to march on Rome. Cleopatra brought her fleet of warships to join those of Antony in the Ambracian Gulf on the Ionian Sea. As Octavian’s armies closed in on Anthony’s forces centered on Actium (on the north side of the Ambracian Gulf), a naval engagement became inevitable. Antony and Cleopatra’s combined fleets numbered about 290 large and heavily-constructed galleys, designed for ramming enemy vessels. Octavian’s fleet numbered about 250 smaller and faster galleys. Antony’s forces had recently suffered from a severe malaria outbreak, resulting in the under-manning of most of his galleys. The two fleets met on the morning of 2 September 31 B.C. in the Gulf of Actium, just outside the Ambracian Gulf. Octavian’s ships were fully manned and his sailors better trained and rested. Octavian’s fleet was generally able to make hit and run attacks on the larger and slower galleys. Thus, the battle slowly tended in favor of Octavian. For some undetermined reason, perhaps thinking that all was lost, Cleopatra signaled her forces to retreat back to Egypt. Antony, seeing Cleopatra’s departure, quickly sailed after her. Antony’s fleet was totally demoralized by these precipitous acts and was soon defeated. After some skirmishes around Alexandria some months later, both Antony and Cleopatra committed suicide. Octavian was given the title “Augustus Caesar” and proclaimed “first citizen” of Rome, effectively marking the beginning of the Roman Empire.