The Battle of Carrhae (53 BCE)

Plutarch, in his Life of Crassus, says that the Parthian horsemen came on “with the noise of a host and the silence of a fire” (Plutarch, Crassus 23), and that the impact of the cataphracts on the Roman square was “as if loosened by some engine of war.” Plutarch was writing more than a century after the event and was working from a chain of Greek and Latin sources (probably beginning with a participant on the Parthian side, possibly Timagenes of Alexandria) that are now mostly lost. The image is his, not the battle’s, and it has shaped how the event has been read in the long centuries since. It is a good image. It is also wrong in two specific ways: the Parthians at Carrhae were not silent, and the cataphract charge did not decide the engagement. The arrows did. The arrows had been falling for hours before the cataphracts appeared, and the Roman army was already breaking when the armoured cavalry finally came in.

This article tries to read the battle as Plutarch’s sources would have understood it, and as the modern scholarship — Bivar, Plutarch’s Crassus in Robin Waterfield’s edition (1999), Rose Mary Sheldon’s commentary, Farrokh’s synthesis — would now describe it.

The political setting

Crassus invaded Parthia in 55 BCE, the year after his second consulship. The political background is well known. The First Triumvirate had been renewed at Luca in 56; Caesar was off to Gaul; Pompey was holding Spain through his legates; and Crassus, sixty years old and the richest man in Rome, wanted a triumph of his own. The expectation that a Parthian war would deliver quick treasure to a Roman state perpetually short of cash was not unreasonable. The Parthian empire of the 50s BCE was at the height of its power, but it was not a military machine in the Roman sense. It had no large infantry, no siege train, no Mediterranean fleet. A short, sharp invasion ought to have been feasible. Plutarch (Crassus 16) records that Crassus himself said, on crossing the Euphrates, that he was marching against “men who fight with slippers and trousers” — a quotation that may be a Roman invention but captures the contemporary Roman view of the Iranian soldier.

The Parthian response was deliberately measured. Orodes II (r. c. 57–38 BCE) took the main royal army east to deal with a potential Armenian invasion — the Armenian king Artavasdes had been negotiating with Crassus — and entrusted the defence of Mesopotamia to Surena. Surena is a striking figure in Parthian history. He was a member of the Suren clan, the hereditary generals of the Parthian empire and a force in Arsacid politics in their own right. The Suren-Pahlav, the chief of the Suren, would over the next century depose and murder several Arsacid kings; Surena’s family was, in effect, the maker of kings. Plutarch, who had access to a fuller account of Surena’s titles and offices than we do, calls him the grand vizier of the Parthian empire, which is probably wrong — the wuzurg-framadar is the correct Middle Persian title, and the office may not yet have existed under that name — but conveys the rank.

Crossing the Euphrates

Crassus crossed the Euphrates at Zeugma in the spring of 53 BCE, with about seven legions. Plutarch’s number of 40,000 (including 4,000 Gallic and German auxiliaries) is probably too high; 35,000 is the modern consensus. His quaestor, Gaius Cassius Longinus — the future assassin of Caesar — urged him to follow the line of the Euphrates, the standard Roman approach to a Mesopotamian campaign. Crassus preferred to move quickly into the interior, perhaps because he wanted to seize the major cities before the Parthian response could consolidate, perhaps because the political calendar at home was unfavourable to long campaigns. The Roman army moved southeast across the plain of northern Mesopotamia, sacking several towns including the Greek city of Ichnae and accepting the surrender of the local population. Plutarch records the gruesome detail of a Parthian governor’s severed head being delivered to Crassus — a token of the Roman advance as much as a war crime.

The Roman army was experienced, well-equipped, and confident. The seven legions were the bulk of Crassus’ consular army, reinforced by auxiliary cavalry and a small number of Greek and Asiatic allies. The Parthian response, by contrast, was initially invisible. Orodes was far to the east, and Surena’s force appears to have kept its distance, observing the Roman column, picking up stragglers, and waiting for the moment to strike.

The first hours

The two armies met on 9 May 53 BCE near Carrhae, on the rolling plain of upper Mesopotamia. Plutarch’s account is detailed enough that the sequence is reasonably clear. The Roman army was drawn up in its traditional formation: heavy infantry in the centre, auxiliary cavalry on the flanks, the baggage train in the rear. The Parthians, instead of the expected distant skirmish line, deployed in two distinct bodies: a first line of horse archers, and behind them, out of sight at first, a body of cataphracts.

The horse archers opened fire at long range with their composite bows, and the Roman infantry formed a defensive square to protect itself from the arrows. The Romans now faced a tactical problem they had not trained for. The horse archers were unengaged at any close distance; the Romans could not reach them with the pilum or the gladius; the square, meanwhile, was under constant arrow fire that grew more accurate as the afternoon wore on. Plutarch’s description of the volley — “the shafts came down like a storm” — is a literary figure, but the underlying observation that the Roman square was being slowly emptied by archery alone is sound. Roman light infantry and auxiliary cavalry charged the horse archers, who retreated, drawing the Roman detachments further from the main body. The horse archers then turned and fired into the pursuers.

I want to underline this point, because it is the part of the battle that is most often garbled in the popular literature. The cataphracts did not begin the engagement. The horse archers did, and they kept the engagement going for several hours. The Roman square was being broken by archery before the cataphracts ever came into view. The Parthian tactical system worked because the missile fire and the shock action were sequential: the one prepared the way for the other, and the second would have been much less effective without the first.

The cataphract charge

The decisive moment, by Plutarch’s account, came when the Parthians, who had been concealing the cataphracts behind a screen of horse archers, suddenly revealed them. The cataphracts charged the Roman square. The impact, on a formation already exhausted by hours of arrow fire and the heat of the Mesopotamian plain, was enough. The Roman line broke, and the surviving infantry fled. Most were killed in the pursuit or captured in the open ground; Crassus himself fell back with a small escort and was killed during a parley, possibly by a Parthian officer, possibly by one of his own men.

The death of Crassus has its own literature. Plutarch, in the Crassus 27, gives the most detailed account: Crassus had begun to retreat from the battle with a small group of Roman officers, and was overtaken by a Parthian detachment. A parley began, and during the parley one of Crassus’ own men — Plutarch names Pomaxathres, a name that is uncertain in the manuscript tradition — or possibly a Parthian officer struck Crassus with a sword, killing him. Plutarch also reports an alternative tradition in which Crassus died in the fighting itself. The “skirmish after the retreat” version is the better attested; the “death in the parley” version is more literary. The two cannot be reconciled, and the truth is unrecoverable.

The famous detail that the Parthians poured molten gold into the mouth of the dead Crassus, mocking his famous wealth, is the moralising centre of Plutarch’s narrative, and the touchstone of the Roman literary tradition on the battle. Plutarch (Crassus 33) gives the story; Cassius Dio mentions it; Florus repeats it; Dante places Crassus in the fourth bolgia of the eighth circle of Hell, where his mouth gapes eternally for the gold that will not come. Whether the story is literal is doubtful. Plutarch himself notes that it is the kind of detail that “the Parthians say,” and most modern scholars treat it as a Roman literary construction designed to drive home the moral that greed is its own punishment. The desecration of corpses, particularly of defeated kings, was a well-attested steppe convention, and the story may have a basis in a real Parthian practice; the molten gold is a Roman flourish.

The standards

The eagle standards (aquilae) of the captured legions were carried to Ctesiphon and paraded in the royal palace. The recovery of the standards became a major Roman political programme. Augustus recovered the Carrhae eagles in 20 BCE, in a diplomatic settlement with Phraates IV. The return was celebrated in Rome with a formal supplicatio and the dedication of the temple of Mars Ultor in the Forum of Augustus, on 1 August 2 BCE. The standards were placed in the temple, and the political programme of ultio (vengeance) was at least symbolically completed. Trajan recaptured Mesopotamia and Ctesiphon in 116 CE; the Parthians under Osroes I briefly recovered some of the older standards in the course of the wars, but the diplomatic record is thin. The full set of standards was returned for good in 62 CE, in the reign of the Parthian king Vologases I and the Roman emperor Nero — a 109-year humiliation that became a Roman literary topos.

Aftermath

Surena did not long survive his triumph. Orodes II, alarmed at the power and prestige the Suren had accumulated, had him executed within a year, on a charge that may have been trumped up. The murder is a useful reminder of the structural instability of the Arsacid state: the king of kings needed the great noble families to fight, and the great noble families could depose and murder kings. Surena’s fate would be repeated under later Arsacids. For the Roman Republic, Carrhae was a catastrophe of a different kind. The destruction of seven legions removed the largest single field force the Republic had ever assembled in the East, and the loss discredited the political system that had produced the triumvirate. The Republic did not long survive Carrhae; within fifteen years, Caesar had crossed the Rubicon, and the civil wars were under way.

Plutarch’s verdict, written with the benefit of long hindsight, is that the defeat at Carrhae was the greatest disaster Rome had ever suffered, and that it was, in the long run, a disaster for the Republic rather than merely for Crassus. The verdict is, in substance, what the Roman Republic believed about itself.