Key Facts
- Date
- 42 BC (two engagements in October)
- Peak force size
- Up to 200,000 men
- First engagement result
- Tactical draw; Cassius died by suicide
- Second engagement
- 23 October 42 BC; Brutus defeated
- Final outcome
- Both Brutus and Cassius dead; Triumvirate victorious
Strategic Narrative Overview
Two engagements were fought on the plain west of Philippi. In the first, Brutus pushed back Octavian and seized his camp, but Antony routed Cassius in the south. Cassius, receiving a false report of total defeat, died by suicide. The first battle was effectively a draw undone by Cassius's death. On 23 October, a second, hard-fought engagement saw Antony and Octavian overwhelm Brutus's forces decisively.
01 / The Origins
The Second Triumvirate — Mark Antony, Octavian, and Lepidus — declared war ostensibly to avenge Julius Caesar's assassination in 44 BC by Brutus, Cassius, and their Liberator allies. Beneath this stated cause lay a deeper struggle between the Optimates, who sought to preserve the traditional Senate-led republic, and the Populares, who championed Caesar's legacy and populist power. Both sides mobilized massive armies and converged on Macedonia.
03 / The Outcome
Defeated in the second engagement, Brutus took his own life, ending organized Republican resistance. With both Liberator commanders dead, the Triumvirate secured undisputed control of the Roman Republic. The battle's outcome paved the way for the eventual power struggle between Antony and Octavian that would transform Rome from republic to empire.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Mark Antony, Octavian.
Side B
1 belligerent
Marcus Junius Brutus, Gaius Cassius Longinus.
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.