Liberators' civil war: Triumvirs Mark Antony and Octavian fight to a draw Caesar's assassins Brutus and Cassius in the first part of the Battle of Philippi, where Cassius commits suicide believing the battle is lost.

The Liberators' civil war was started by the Second Triumvirate to avenge Julius Caesar's assassination. The war was fought by the forces of Mark Antony and Octavian against the forces of Caesar's assassins, led by Marcus Junius Brutus and Gaius Cassius Longinus, referred to as the Liberatores. The latter were defeated by the Triumvirs at the Battle of Philippi in October 42 BC, and committed suicide. Brutus committed suicide after the second part of the battle.

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.

Gaius Julius Caesar Augustus, also known as Octavian, was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in AD 14. The reign of Augustus initiated an imperial cult and an era of imperial peace in which the Roman world was largely free of armed conflict. The Principate system of government was established during his reign and lasted until the Crisis of the Third Century.

Marcus Junius Brutus was a Roman politician, orator, and the most famous of the assassins of Julius Caesar. After being adopted by a relative, he used the name Quintus Servilius Caepio Brutus, which was retained as his legal name. He is often referred to simply as Brutus.