53 BCE

An engraving of the Battle of Carrhae in 53 BCE shows the Parthian cavalry engaging the legions of Marcus Crassus in what proved to be one of the greatest military disasters suffered by the Roman army.

The English expression ‘parting shot’ derives from ‘Parthian shot’, a term used to describe the deadly tactical practice of the mounted archers of the Parthian Empire, who could swivel on their horses and fire an arrow while riding away from their enemy. This skill was used to catastrophic effect against a large Roman army led by Marcus Crassus, famous for his ruthless suppression of the Spartacus revolt. In the context of the ancient world, where military innovation was slow to evolve, the Parthians made the most of their unorthodox military equipment and fluid battle tactics against a Roman army used to fighting and winning on its own terms. What followed on the arid plains of what is now southeast Turkey was probably the worst defeat suffered by a Roman army throughout the entire period of Roman domination of the Mediterranean basin and Middle East.

There is no general agreement about why Crassus was there in the first place. The Parthian Empire, stretching across modern Iran and Iraq, was founded in the late third century BCE by invaders from northeast Persia, and its powerful warrior caste successfully kept the menacing Roman Empire at bay roughly along the line of the River Euphrates. Crassus was a member of the First Triumvirate, ruling the empire together with Julius Caesar and Gnaeus Pompey. Their rule was divided up territorially and Crassus claimed Syria, where he arrived in 54 BCE, intent either on adding to his already legendary wealth or securing military victories against a new enemy to enhance his own political stock in Rome. His son Publius, who had been campaigning in Gaul with Caesar, was keen to raise his own reputation and obtained permission to travel with 1,000 Gallic horsemen to join his father in the campaign planned against distant Parthia.

The Parthian king, Orodes II, knew well in advance of the arrival and probable intention of the invading Roman army, but he needed to be sure that Crassus would not join up with other local kings in an anti-Parthian alliance. The King of Armenia, Artavasdes II, not only offered Crassus large bodies of men, including 6,000 cavalry, but also advised him to attack the Parthians by moving through the mountains in southern Armenia, where infantry were better able to fight and the Parthian cavalry would be at a disadvantage. Crassus refused both offers (though the 6,000 horsemen joined his army), perhaps because he thought the size of the army he had gathered – around 40,000 legionaries, 4,000 cavalry and 4,000 light infantry – would easily overcome a force of desert horsemen. In spring 53 BCE, he set off with his army from northern Syria to attack Parthia directly and seize the major city of Seleucia. He knew almost nothing about his enemy or his whereabouts.

Orodes had not been idle. He moved a large army to Armenia to intimidate the king and prevent Armenian forces from linking with Crassus. He left his lieutenant Surena as commanding general (spahbod) of 9,000 light horsemen and 1,000 heavily armoured cavalry, or cataphracts (no more than a quarter the strength of the approaching Roman army), with orders to harass and hold up the Roman approach. The light horsemen were armed with a powerful composite bow made of laminated wood and sinew, which they fired as they rode. The impact of the arrows from close range was considerable. There remains dispute about whether they could penetrate Roman body armour effectively, though the barbed arrows could inflict serious wounds on exposed arms, legs and faces. The real innovation on the Parthian side was the cataphract, a warrior covered with scale armour of bronze and steel plates protecting most of the rider’s body, as well as the horse. They each carried a long heavy lance, or kontos, twice the length of the Roman javelins. The Roman legionaries were armed with the standard short sword, spear and shield, but had nothing that would allow them to come to grips with their mobile opponents, forerunners of the knights who later dominated medieval warfare.

The novel warfare practised by the Parthians proved enough to compensate for the great gulf in size between the two sides. Crassus relied on an Arab guide, Ariamnes, for his route, but he was in the pay of Orodes and led Crassus into a trap across largely waterless desert, where the Parthian horsemen would be in their element. They passed the small town of Carrhae, which was already garrisoned by Roman soldiers, crossed a minor stream (where it is alleged that Crassus would not allow his thirsty troops to drink) and finally saw and heard the Parthian enemy ahead of them. Loud drums beat out a constant rhythm while the horsemen kicked up clouds of sandy dust around them. The cataphracts advanced with blankets shrouding their armour. Crassus was uncertain how to meet this odd formation. After trying a conventional line, he opted for a large square, with the cohorts each protected by a small squadron of Roman cavalry. It turned out that this was the worst formation he could have chosen.

At some point towards mid-day the Parthians attacked. The cataphracts threw off their covering, revealing armour, according to one ancient account, ‘blazing like fire’ in the hot sun. Surena sent his horsemen first, galloping at speed around the whole Roman square, firing arrows at will because the Roman soldiers were so closely packed together. Crassus first sent his light infantry to try to drive them off, but they were deluged with arrows and hurried back to the shelter of the square. Frustrated at being unable to get at an enemy who had already inflicted heavy casualties on his soldiers, Crassus sent his son Publius with 1,300 cavalry, 500 archers and 4,000 infantry to eliminate the threat from the enemy bowmen. Publius rashly followed where the Parthian horses fled only to discover, at some distance from the main army, that the cataphracts were drawn up in a solid phalanx waiting to charge. The heavily armoured cavalry crashed into the Roman force, while the lighter horsemen kept up a volley of arrows, replenished throughout the battle by a large reserve of missiles carried by 1,000 camels. All but 500 of the force were slaughtered. Badly injured, Publius ordered his shield-bearer to kill him, while his Gallic horsemen fought to a blood-soaked standstill.

An nineteenth-century manuscript depicts the Parthians’ use of metal plates to protect both rider and horse, and the technique of turning to shoot the arrow over the back of the horse, a tactic to which the Roman infantry found no answer.

The extent of the disaster was brought home to Crassus when he saw a Parthian lance carrying the severed head of his son. His Roman legionaries tried to keep close order as they were subjected to repeated charges from the cataphracts trying to break the Roman line, and a relentless wave of arrows began to eat away at Roman strength. Only when night fell did the killing stop, with few of the Parthians slain but thousands of injured, dying and dead legionaries piled on the sandy soil. Crassus ordered a retreat back to Carrhae, leaving, it was estimated, 4,000 wounded to be killed by the Parthians. The surviving army began to break up and move back to Syria. Crassus was invited to parley with Surena, but an altercation between the delegations ended with the murder of Crassus and his senior officers. Molten gold, it was claimed, was poured down the throat of his corpse as mocking retribution for his greed. The vast Roman army lost 20,000 dead and 10,000 captured. Later Roman accounts blamed Crassus for military incompetence, for which there was some justification, but the problem for Rome was the unconventional tactics they confronted. With the Romans unable to conquer Parthia, the Euphrates remained their unstable frontier.