The Battle of Mount Gindarus or battle of Cyrrhestica in 38 BC was a decisive victory for the Roman general Publius Ventidius Bassus over the Parthian army of Pacorus the son of King Orodes on the Greater Syria district of Cyrrhestica.
After the defeat of the Roman army under Crassus at the Battle of Carrhae the Parthian forces made a number of raids into Roman territory. The Romans under Gaius Cassius Longinus,a survivor of the battle of Carrhae who became proquaestor defended the border against these Parthian incursions.
However the Parthians returned in 40 BC with an even larger force, along with the rebel Roman Quintus Labienus at their service. This force defeated the Roman governor of Syria and proceeded to over-run the province. Many of Roman troops in Syria at the time had been former Republicans who had once fought against Mark Anthony in the service Brutus and Cassius. Many may have gone over to their fellow Republican Quintus Labienus in joining the Parthian invaders further weakening the Roman position in the east. In order to counter the Parthian gains Mark Anthony gave Publius Ventidius Bassus the command of several legions. Publius Ventidius Bassus learned from Crassuses errors and made sure that his forces had sufficient fire power in the form of archers and slingers for heavy infantry by itself was vulnerable to the mobile Parthian horse-archers. He also recognised that flat ground favoured the Parthian cavalry whereas hilly terrain would nullify this advantage.
Publius Ventidius Bassus fought and defeated Quintus Labienus and the Parthian general Phranipates in Asia Minor, Quintus Labienus attempted to disguise himself and flee, however he was caught by Ventidius's forces and then executed. The Parthians were forced to withdraw to Amanus Pass where they yet again met Ventidius' forces, the Romans emerged victorious and the Parthians redrew from Syria.
The Partians after this setback launched another invasion into Syria in 38 BC led by Pacorus the son of King Orodes. Ventidius in order to gain time sent spies to Pacorus who suggested that he should cross the Euphrates River at their usual ford. Pacorus did not trust this information and decided to cross the river much farther downstream, this is what Ventidius hoped would occur and gave him time to get his forces ready.
The Parthians faced no opposition to their river crossing and proceeded to the town of Gindarus in Cyrrhestica confidently due to their belief that their Roman foes were weak or cowardly on the grounds that they did not attempt to prevent their river crossing.
When the Parthians got to the town which sat on a small hill they encountered Roman battle legions confidently formed in battle order on the slopes. The Parthians rushed to attack, whether this order came from Pacorus or was a spontaneous charge is unknown, in either case Ventidius ordered his troops who had the advantage of high ground to attack the horse-archers advancing up the slope. The horse-archers were forced into close-quartered combat against the legionnaires and suffered heavily for it for they were unsuited for such combat. The Parthian cavalry's will eventually broke and panic spread, many of the horse archers were driven down the slope were they crashed into their fellow companions due to their desperation to escape. The horse-archers eventually fled or fell. Parthian heavy cavalry which was stationed at the bottom of the hill was enveloped and surrounded by the legionnaires. Instead of immediately attacking with the legionnaires Ventidius made use of his slingers to rain down projectiles on the Parthian heavey cavalry which included Pacorus himself. After the barrage was lifted the legionnaires moved in and were quickly able to identify Pacorus because of his standard and expensive armour. Pacorus was eventually slain along with his bodyguards, the remaining cavalry broke and attempted to flee their entrapment which some managed to do. Overall the Roman army had achieved a complete victory.
Ventidius had anticipated that the Parthians if defeated would attempt to flee the way they came and so he had Roman infantry and cavalry lay in wait for the Persians as they made their way back towards the Euphrates, the fleeing Persians that were caught were destroyed. Ventidius after having met Pacorus' large army in Cyrrhestica and after inflicting an overwhelming defeat on the Parthians had succeeded in securing Rome's eastern provinces. Ventidius if he wished could have pursued the Parthians even further, but did not want to incur Antony's jealousy, so he instead subdued those who had rebelled against Rom
