After the assassination of Julius Caesar in 44 BC, there was a civil war between the Caesarians, the supporters of Caesar, and the Pompeians, the supporters of Pompey, who had led the forces of the Roman senate against Caesar during Caesar's Civil War (49-45 BC). In this civil war, the Liberators' Civil War (43-42 BC), the Pompeians were led by Gaius Cassius Longinus and Marcus Junius Brutus the Younger, the leaders of the conspiracy to murder Caesar. They fought against Octavian and Mark Antony, two members of the Second Triumvirate, an alliance between the three leaders of the Caesarians. Cassius and Brutus were defeated at the Battle of Phillipi in October 42 BC. Labienus tried to resurrect the Pompeian cause with the help of the Parthians.