Quintus Labienus
Quintus Labienus Parthicus (died 39 BC) was a Roman general of the late Republic, the son of Titus Labienus, who had served as a key lieutenant to Julius Caesar before defecting to Pompey during the Civil War.[1] A staunch Republican, Quintus fought under the assassins of Caesar, including at the Battle of Philippi in 42 BC, where the Optimates were decisively defeated by the forces of Octavian and Mark Antony.[2] Following this loss, he sought refuge at the Parthian court of King Orodes II, forging an alliance that enabled him to lead Parthian armies in a major incursion into Roman eastern provinces.[1] In 40 BC, Labienus, alongside Parthian crown prince Pacorus I, spearheaded an invasion of Syria, exploiting Roman disarray from the Perusine War; their forces swiftly overran the province, capturing Antioch and much of Asia Minor, while Labienus assumed the title imperator Parthicus and minted coins proclaiming Parthian victory over Rome.[3] These successes briefly restored Republican influence in the East and supported figures like Antigonus in Judaea against Herodian claimants, but they were short-lived.[2] Roman countermeasures under Publius Ventidius Bassus culminated in decisive victories, including at the Cilician Gates, forcing Labienus to flee; he was pursued and slain near the Taurus Mountains, marking the end of significant Republican-Parthian collaboration. Primary accounts from Cassius Dio and Appian highlight Labienus's role as a opportunistic defector leveraging foreign aid against the Triumvirate, though his ambitions ultimately faltered against renewed Roman cohesion.[3]