II.

The Second Triumvirate

Caesar’s assassination plunged Rome into turmoil. Octavian, determined to avenge his adoptive father and secure his own place, vied with Mark Antony, Caesar’s ambitious colleague, for power and honor. After some preliminary skirmishes, both political and military, during which Antony was driven across the Alps while Octavian was made senator and then consul, Octavian recognized the necessity of making peace with his rival. In late 43 bc, therefore, the two—joined by Antony’s ally, the general Marcus Aemilius Lepidus—met and formed the Second Triumvirate to rule the Roman domains. The alliance was sealed by a massive proscription, in which 300 senators and 200 knights—the triumvirs’ enemies—were slain. Among those killed was the aging orator Cicero.

Octavian and Antony next took the field against the leaders of Caesar’s assassins, Marcus Junius Brutus and Gaius Cassius Longinus, both of whom committed suicide in 42 bc, after being defeated at Philippi in Macedonia. By 40 bc the triumvirs had divided the Roman world among them. Octavian was in control of most of the western provinces and Antony of the eastern ones; Lepidus was given Africa. Although Antony and Octavian clashed over the control of Italy, they patched up their differences, and Octavian gave Antony his sister, Octavia, in marriage. In 36 bc, Sextus Pompeius, son of Pompey the Great and the last major enemy of the triumvirs, was eliminated. Octavian then forced Lepidus from power, while Antony was in the east fighting the Parthians.

The triumvirate was now breaking up. Having sent Octavia back to Rome, Antony soon married Cleopatra, whom Caesar had installed as queen of Egypt, and recognized Caesarion, her son by Caesar, as her co-ruler. This undercut Octavian’s position as the only son of Caesar, and war was inevitable. He defeated Antony and Cleopatra’s forces in a naval battle off Actium in 31 bc; they both killed themselves the following year. Caesarion was murdered. In 29 bc Octavian returned to Rome in triumph, at age 34 the sole master of the Roman world.