Warfare & the Army

The army was the instrument by which a petty kingdom of Persis became, within a generation, the largest empire the world had yet seen, and by which it was held for two centuries. Yet it is oddly hard to see. The kings' own inscriptions almost never describe their forces; the administrative tablets record soldiers only as men drawing rations or holding land; and the fullest narratives, the ones every schoolbook draws on, are Greek, written by the enemy, and shaped by a literary image of the barbarian host that has proven very difficult to see past. This survey sets the received picture beside the documentary and archaeological evidence, following the specialist scholarship, above all Sean Manning's Armed Force in the Teispid-Achaemenid Empire (2020), in being cautious about what the Greek tradition really lets us know.

The composition: the levy and the standing guard

An Achaemenid army was two things joined together. At its heart was a small standing force of professional soldiers, kept under arms the year round; around that gathered, when a great campaign required it, a seasonal levy drawn from the subject nations of the empire. The standing core answered to the King of Kings as commander-in-chief, a constant across the whole dynasty even when the king delegated a campaign to a general; the levy was raised through the satraps, each of whom held forces in his province, subject to an annual royal review of their arms and horses, and could be called to bring his contingent to the muster (the picture drawn in Christopher Hassan's Companion chapter on army structure).^[1] The satrapal armies could combine into a powerful temporary coalition, as they did to face Alexander at the Granicus; above the satraps, in the later empire, a regional marshal the Greeks called the kāranos might hold command over several provinces at once.

The organisation of the standing army was decimal, and the philologists have recovered its ladder of command from Old Persian words surviving in Greek, Elamite and Akkadian: a file of ten under a daθapati, a hundred, a thousand under a hazārapati (the "commander of a thousand" whom Greek sources remember), and a corps of ten thousand. Herodotus describes exactly this structure, regiments of ten thousand broken into thousands, hundreds and tens, and the survival of the word hazārapati in independent sources supports him (Shahbazi, Encyclopaedia Iranica, "Army i").^[2]

The most famous single body was that standing corps of ten thousand elite Iranian foot, whom Herodotus calls the Immortals:

"These Persians were called 'Immortals,' because, if any one of them made the number incomplete, being overcome either by death or disease, another man was chosen to his place, and they were never either more or fewer than ten thousand." (Herodotus 7.83, trans. Macaulay)^[3]

The name has a well-known difficulty behind it. "Immortals" is Herodotus's Greek word, athanatoi, and a widely represented view holds that it renders a misheard Old Persian term: the guard may have been the anūšiya, the "companions" or "followers" of the king, the word confused with anauša, "immortal" (a caution registered in Iranica's "Army i" and in the compendium's own research notes).^[2] It is worth adding two further cautions the sources force on us. First, the Immortals belong overwhelmingly to Xerxes' invasion narrative; to speak of "the Immortals of Darius" over-attributes a body most vividly attested a reign later. Second, distinct from them marched a thousand spearmen of the noblest Persians whose spear-butts were shaped as golden apples, the "Apple-bearers" (Herodotus 7.41), the king's own bodyguard, in which Darius himself had served under Cambyses; modern discussion (M. B. Charles; and the Companion's chapter on organisation, by Christopher Tuplin and Bruno Jacobs) has laboured to keep these overlapping elite units apart, and warns that after Thermopylae the Immortals more or less vanish from the battle narratives, so that their tactical role stays obscure.^[1]

Beyond this professional heart, the mass of an imperial army was a levy. Every Persian male, on the reconstruction drawn from Strabo and Xenophon, owed service, and men held estates in return for the obligation to muster armed and equipped, most clearly documented in the ḫaṭru land-for-service system of Achaemenid Babylonia, where a plot of "bow land" or "horse land" carried the duty to send a bowman or a cavalryman when the crown called. To gather such a host from across a continent took a long time, sometimes years; this is one reason the empire kept garrisons at its strategic nodes, the best-documented being the Jewish and Aramean soldiers of the frontier garrison at Elephantine in Egypt, organised in detachments and serving the crown directly.

The shield-bearers, the bow and the spear

The distinctive Persian infantry formation set a front rank of large shields before files of archers. The shield, the gerron of the Greek texts, was a light thing of sticks threaded through a wet sheet of leather, tough enough to stop an arrow and carrying no metal; the big rectangular type could be planted in the ground to make a standing wall from behind which the bowmen shot. The shield-bearer is caught in an Old Persian word surviving only in a Greek gloss, reconstructed as \spara-bara, and it has become convenient, if not strictly warranted by the evidence, to call this Herodotean Persian infantry sparabarai (the terminology is dissected by Manning, pp. 293-295).^[4] Farrokh reconstructs the file as ten shield-bearers in front of nine rows of infantry-archers, the shieldmen themselves carrying a spear for the moment the enemy closed (Farrokh, Shadows in the Desert*, p. 78).^[5]

The bow was the national weapon, the arm a Persian boy was reared to and the sign of the king himself, who holds it on his tomb relief and on the daric. The composite bow, of horn and wood and sinew, was a short weapon with a long weapon's power. Beside it the Persian carried the akinakes, the short two-edged dagger-sword strapped to the thigh in the "Median" riding costume, and, above all, the spear. Darius set the two weapons at the centre of the ideal he cut on his tomb:

"As a horseman I am a good horseman; as a bowman I am a good bowman, both afoot and on horseback; as a spearman I am a good spearman, both afoot and on horseback." (Darius I, his tomb at Naqsh-e Rostam, DNb)^[6]

The importance of the spear is easy to underrate, because the Greek tradition worked hard to make the Persian an archer and the Greek a spearman. Yet at Naqsh-e Rostam Darius bids the viewer read the reach of Persian arms in the very peoples who bear up his throne:

"How many are the countries which Darius the king held? Look at the sculpted figures which bear the throne platform. Then you shall perceive and it will become known to you that the spear of the Persian man has gone far." (Darius I, his tomb at Naqsh-e Rostam, DNa)^[6]

On the reliefs of Persepolis, too, there are more spears than bows. Herodotus' claim (7.61, 7.211) that Persian spears were markedly shorter than Greek ones, endlessly repeated by modern narrators, is not supported by the art, in which spears both Greek and Persian run from about the height of the bearer to a third longer; Manning shows the "short spear" to be a rhetorical cliché, embedded by Herodotus in a discourse about soft eastern and hard western manhood, and argues there is no basis for calling the other Persian weapons inferior either (Manning, pp. 295-299).^[4] The body armour was scale, of bronze or iron, "like the scales of a fish" in Herodotus' phrase, though he himself implies it was not universal: when he divides the Persians after Salamis into Immortals, cuirass-bearers and unarmoured men, he lets us see that armour marked out some soldiers and not others, exactly as in a Greek army.

The horse and the scythed chariot

Cavalry was the arm of the nobility and of the northern and eastern Iranians, the Saka above all, who fought as mounted bowmen. The horseman of Media wore the trouser-and-tunic riding suit, carried the bow, the akinakes and a pair of javelins or a thrusting spear (the Greeks' palton), and rode the fine Nisaean horses without stirrup or true saddle, holding his seat by the grip of his knees. Manning devotes careful attention to the special economics of cavalry: a good horse was ruinously expensive and a fragile asset, and the arrangements by which a would-be cavalryman borrowed or was compensated for his mount, so often read as signs of a decayed feudal levy, turn out to have close parallels in societies whose cavalry no one calls decadent, from the loan (katastasis) the city of Athens made its horsemen to the horse-troubles of British officers at Waterloo (Manning, pp. 209-211).^[4]

The scythed chariot is a special case, and a cautionary one. In the modern imagination it is a signature Persian weapon; in the evidence it is, in Manning's words, "essentially a creature of Greek and Latin literature." No depiction of one survives from any place and time where they were actually used; the weapon first appears in Ctesias' tales of the legendary King Ninus and in Xenophon, and thereafter becomes a fixed symbol of the exotic, fumbling armies of the East, prominent in the stories of Gaugamela and later of Mithridates, retold with growing relish by writers who had never seen a phalanx, let alone a scythed car (Manning, pp. 269-271).^[4] It is a clean instance of how a vivid literary image can outrun, and then stand in for, the thing itself.

The ethnic contingents and Herodotus' great army-list

The set-piece description of the imperial army is Herodotus' catalogue of the nations Xerxes led against Greece (7.61-99), nation after nation in its own dress and arms: Persians and Medes in scale and tiara, Assyrians in bronze helmets, Saka in their pointed caps, Indians in cotton with cane bows, Ethiopians painted in vermilion and chalk, Arabs on camels, forty-six peoples in all. It is a magnificent piece of writing, and it must not be read as a muster-roll. Tuplin and Jacobs note that its military diversity is more folkloristic than real, that as a list of nations it simply rearranges the disputed tribute-list of Book 3, and that its historical integrity was already being questioned a generation ago; Pierre Briant read its exotic elements as a parade contingent got up for ideological display rather than a fighting order of battle (Companion, Tuplin & Jacobs, "Military Organization and Equipment").^[1] The catalogue tells us how the Persians wished their empire's unity-in-diversity to be seen, and how a Greek imagined the whole world marching under one king; it is poor evidence for who actually stood in a battle line, where the sober narratives show a Persian and Iranian core with foreign auxiliaries and, in the later empire, hired Greek hoplites, positioned by ground and tactics rather than by ethnography.

The hardest part of the catalogue is its numbers, and here the modern correction is at its sharpest. Herodotus builds his host into the millions; no serious historian believes the figure, yet, as T. Cuyler Young observed, even the sceptics have tended to leave the Persians with one of the largest armies in world history, so strong is the pull of the "greatest war ever" (Manning, pp. 319-320).^[4] Manning sets out the case against the millions on grounds not of arithmetic but of logistics and command. Armies of hundreds of thousands, coordinated across a theatre, are a creature of the age of general staffs and mass literacy, first verifiable in the Napoleonic wars; an ancient army spent nearly all its time massed together, drawing water and fodder from a single corridor, waiting its turn at every ford and pass, and could not be split and reassembled at will. The very large numbers, Manning argues, are found only in the classical and biblical traditions, never in the cuneiform record, where even the Assyrian kings claim no more than 120,000; the idea that vast armies are characteristically Near Eastern is itself a Greek and Hebrew literary inheritance, not a fact of the East. Estimating an army's size was a genuinely difficult task even for the general who owned it, full of chances for error and inflation, and Herodotus is explicit that his grand totals are the product of his own calculation, not of any document. The prudent modern estimates for Xerxes' field army run in the low hundreds of thousands at the most, and quite possibly less.

Supply, pay and the sinews of war

The logistical arm is less visible than the fighting one, but it was formidable. For the invasion of Greece, Herodotus describes supply depots stocked in advance with grain, water and fodder along the line of march, and a heavy requisition of provisions from the nations the army passed through (7.25, 7.118-120); Cambyses' march on Egypt was prepared by securing water-caches across the Sinai through a pact with the Arabs, and by ensuring a sea-borne supply line before the army moved (the logistical evidence is gathered in Hassan's Companion chapter). At the level of the individual soldier, the Babylonian documents let us watch the system work from below: contracts like the well-known Gadal-iāma text record exactly what equipment a landholder was to bring to the muster, down to the horse, the armour and the arrows.^[7] Manning's reading of these documents overturns an old story. The substitution of cash for personal service, and the borrowing of horses and gear, long read as symptoms of a military gone soft, were in fact sensible responses to a universal problem, that those best able to bear the expense of war (the older and propertied) are not always those most willing to fight; the same solutions appear in medieval Europe's scutage and in the American Civil War's commutation, and none of them shows an army in decay (Manning, pp. 205-213).

The navy

The empire was a land power that acquired, when it needed one, a first-class fleet, for it did not build ships or man them from Persia. The war-fleets were furnished by the maritime subject peoples, the Phoenicians above all, with the Ionian Greeks, the Egyptians and the Cypriots; the king ordered their construction as requirement dictated and crewed them from these seafaring nations (Hassan's chapter, following Wallinga). Each ship, Farrokh notes, carried a command contingent of thirty Iranians, Persians, Medes or Saka, under a captain called the navpati (Farrokh, Shadows in the Desert, p. 77).^[5] Herodotus gives Xerxes a fighting fleet of 1,207 triremes, and here too the round figure invites the same scepticism as the army totals. The Phoenician squadrons carried a special cachet, and it was the loss of the fleet in the narrows at Salamis, more than any defeat on land, that broke the invasion of Greece, a reversal the Athenian veteran Aeschylus staged for his own city within a decade.

Fortification and siege

Siege warfare is thinly documented for the early empire, which is itself significant. The Persians took great cities, Sardis and Babylon fell to Cyrus, and Herodotus's account of the siege of Sardis is among the first glimpses of the army's camel baggage-train. But the elaborate siege-train of towers, rams and engines that the Greek and Roman world associates with the taking of walls is largely a later development; where the early Achaemenids reduced a fortified place they seem to have done so by blockade, escalade, stratagem or treachery as often as by engineering (Manning, pp. 334-343). The empire's own fortifications, the garrisoned strongpoints at the satrapal seats and frontier posts, were the more constant military fact, the network by which a small standing force held a vast territory between the rare great campaigns.

The army in the sources: the horde and the reality

Running through every section of this survey is a single problem: the Greek image of the Persian army, and how far to trust it. That image is of a vast, gaudy, ill-disciplined oriental horde, brave enough but soft, winning by weight of numbers and losing to the hard free spearman of the West; and it hardened, after the Persian Wars, into a rhetoric of eastern effeminacy that the sources deploy with real artistry. Herodotus himself, Manning shows, both used the stereotypes and quietly undermined them for the careful reader, granting the Persians at Plataea equal courage and strength and setting their defeat down to training and equipment rather than manhood. He can even lend the King's men their own bewildered dignity, as at Marathon, where the horde watches a handful of Greeks do the unthinkable:

"The Persians seeing them advancing to the attack at a run, made preparations to receive them; and in their minds they charged the Athenians with madness which must be fatal, seeing that they were few and yet were pressing forwards at a run, having neither cavalry nor archers." (Herodotus 6.112, trans. Macaulay)^[3] The later and cruder version of the story became a thesis of decline: that the Achaemenid army decayed across two centuries into a rabble propped up by hired Greeks, effeminate and overtaxed, ripe for Alexander. Farrokh, writing a broad military history, still tells it largely this way, that "over time the nature of the army changed... less of a professional army," until the kings hired Greeks to fight their battles (Farrokh, Shadows in the Desert).^[5] Manning's book is, in large part, a sustained dismantling of that thesis: the reliance on paid professionals was a rational and widespread military evolution, not a moral collapse; the cash-for-service arrangements were sound estate management, not decadence; and the whole "decline" was constructed from documents (the Babylonian bow-estates) read through assumptions that no longer stand.^[4] The army that met Alexander was not obviously worse than the one that met the Greeks a century and a half before; it simply met a better one.

How we know

The evidence is lopsided, and the survey has tried to weight it accordingly. The kings' inscriptions are contemporary and Persian but say almost nothing about how armies were organised or fought; the reliefs of Persepolis and Susa show ranks of spear-bearers and guardsmen in ceremony, not battle; the cuneiform and Aramaic documents are precious for organisation, land-tenure, pay and supply but describe individual soldiers, not campaigns; and the connected narratives are Greek, late for the early reigns, written by adversaries, and saturated with a literary tradition about barbarian hosts. The soundest procedure, and the one followed here, is to let the documents and the archaeology set the frame and to read the Greek narratives against it, sceptical of the millions, of the short spears, of the scythed chariots and of the tale of decline, while still granting Herodotus his due as a witness who often knew more than he is given credit for. The positions this survey takes, a professional core plus a slow-gathered levy, the bow and the spear together rather than the bow alone, army numbers in the hundreds of thousands at most, and no long decadence, reflect the current specialist mainstream, above all Manning 2020, while leaving the genuine uncertainties, the true size of the guard, the reading of anūšiya, the scale of the greatest hosts, honestly open.^[8]