The Battle of Philippi was the final battle in the Liberators' civil war between the forces of Mark Antony and Octavian and the leaders of Julius Caesar's assassination, Brutus and Cassius, in 42 BC, at Philippi in Macedonia. The Second Triumvirate declared the civil war ostensibly to avenge Julius Caesar's assassination in 44 BC, but the underlying cause was a long-brewing conflict between the so-called Optimates and the so-called Populares.

Marcus Antonius, commonly known in English as Mark Antony, was a Roman politician and general who played a critical role in the transformation of the Roman Republic from a constitutional republic into the autocratic Roman Empire.