Persian military forces were drawn from all areas of the Empire, members of the elite corps as well as conscripts levied for local action or for major campaigns. Thus the label “Persian” is not to be understood as describing the ethnic makeup but rather the troops’ allegiance, fighting under Persian officials or commanders. As has been seen, however, the command structure was not thoroughly Persian by any means either, save at the very top of the hierarchy, including most satraps and of course the King himself. The Old Persian word kra may be translated either as “army” or as “people.” This reveals the army’s ultimate origin – among the Persians themselves, many of whom came to form the corps of the standing army – as it results in occasional confusion in modern translation. When kra appears in a text, it is not always evident to us whether the people as a collective group or the specific subset of the army is meant.
Herodotus gives a full and colorful account of the vast and diverse forces of the imperial levy, the full army and navy of Persians and subject peoples, when he tallies the vast forces that Xerxes arrayed against Greece in 480 BCE. Herodotus also names many of the commanders, an elaborate depiction of the peoples of the Empire with descriptions of their clothing and equipment (7.61–100). For example, both Persians and Medes were arrayed in felt caps, colored tunics over scale mail, trousers, wickerwork shields, and a variety of weapons. Ethiopians (Nubians) wore leopard or lion skins and carried large bows. Paphlagonians wore woven helmets and carried small shields and spears. That Herodotus’ entire portrayal better describes a parade than a battle array has long been understood. But it typifies the diversity of peoples and weaponry that the Persian commanders had to weld into an effective fighting force. Persian forces, both infantry and cavalry, were renowned for their use of the bow: a frequent tactic was the unleashing of storms of arrows from behind a shield wall or for horsemen to harry the enemy with volleys of arrows.
Scholars debate the effectiveness of the Persian forces’ armor and tactics especially in the context of Xerxes’ invasion of Greece in 480 and Alexander’s invasion of the Persian Empire in the late 330s. Herodotus (9.62) describes the final crush of the Persians against the Spartans at the Battle of Plataea in 479:
On the one hand the Persians were no less than the Greeks in courage
and strength, but the Persians were without shields and, beyond this,
were unskilled and not the equal of their opponents in experience.
This passage offers just one example of the persistent problems of source evaluation. When Herodotus says that the Persians were “without shields” (Greek anoploi), what does that mean? Were the shields lost in battle? Was this contingent of the Persian army simply not carrying shields? And which group was it, ethnic Persians or some other? Some translate anoploi as “without armor,” which adds another layer to the problem. The Spartans were the most (by far) professionalized Greek soldiers of their day, so even the elite corps of the Persian army would have had their hands full against them. Beyond the elite, levied troops from the provinces of course did not have the same sort of armor, weaponry, or tactics as did, for example, the Persian Immortals and similar contingents. Numerous other passages in Greek sources provide similar perspectives: heavily armed Greek infantry, fighting in tight phalanx formations, trumped the (as generally described in Greek sources) light armed, less experienced, inferior Persian infantry every time – except when they did not. It is difficult to sift the Greek stereotypes from the realities of individual battles. That the Persians were able to conquer and retain so much territory for so long testifies to their army’s effectiveness.
The elite Persian force, numbering 10,000 according to Herodotus (7.83), was called the Immortals. Whenever one of their number died or was wounded or ill, another would take his place so the number of the battalion always remained 10,000. They were the most effective, and feared, Persian infantry force, and clearly comprised elite members of Persian society: men of prominent families or high rank. One thousand of them had gold pomegranates on their spears, some of whom comprised the king’s personal bodyguard, and the other 9,000 had silver. Herodotus’ incidental detail that the Immortals were conspicuous for their gold (bracelets or other marks of status and honor), and that they were accompanied by wagons bearing concubines and many servants, indicates that we are not dealing with the rank and file. Prestige items are frequently mentioned in conjunction with Persian officers and nobles, a phenomenon that also fed Greek stereotypes of Persian effeminacy and weakness. But these items were more symbolic than practical and communicated entirely different messages – honor and status – in a Persian context.
Greek sources often highlight the prominence and skill of Greek mercenaries, and from that perspective it was only thanks to better trained and better equipped Greek professionals that the Empire was able to field any sort of worthwhile fighting force in the fourth century. This trope contributed heavily to the stereotype of the effeminate, decaying Persian Empire before its fall to Alexander the Great. And even though Greek mercenary forces were an increasing phenomenon in the fourth century, and certainly used by Persian commanders, their significance often seems overestimated in Greek sources.
Herodotus describes the arms and equipment of Xerxes’ army in some detail. The Persians themselves wore floppy felt hats, tunics and armour exhibiting a surface of fishlike iron scales, and trousers. They carried wicker shields. Their weapons were large bows, short spears and daggers which were suspended from the belts on the right-hand side. Thus equipped, they might or might not be mounted. Persian armies generally relied upon the large numbers of their horsemen and bowmen.
Apart from the Persians themselves, Herodotus gives particulars of the other national contingents which the Persian kings were able to mobilize, although the statistics on which he based his information may have referred to the potential fighting strength of the entire Persian Empire rather than to Xerxes’ expeditionary force, gigantic though this force unquestionably was. We hear of Assyrians and others with bronze helmets; but in general, the Asiatics were protected only by various kinds of soft headgear and they seem to have worn no substantial body armour. Apart from daggers, bows and arrows, their weapons included iron-spiked clubs, axes and lassoes.
Cavalrymen – especially cavalry officers – may have worn more protective armour. Masistius, the Persian cavalry commander who was killed in the early stages of the Plataea campaign, wore gold scale armour under his scarlet surcoat. When his horse was hit by an arrow, he defended himself vigorously on foot and could not be brought down by body blows. At last, the Athenians who surrounded him guessed the secret and struck at his face.
Persian archers, both mounted and unmounted, carried their arrows in a quiver slung on the hip. This practice differed from that of the Greek archers whose quivers were slung on their backs. The hip position was no doubt more expeditious when there was a requirement for rapid fire.
Herodotus refers to the war chariots of the Indian contingent, but there is no mention of these chariots being used in the fighting. Persian kings normally went to war in chariots, which were also employed by the Persians for hunting. The Greeks of the classical period used chariots only for sporting events. Generally speaking, by the time of the Persian Wars the war chariot had been replaced by the man on horseback. The change had no doubt been brought about by the improved efficiency of horses’ bits, which made it easier for the rider to control his steed.
The Persian High Command
The Persian numbers in the two invasions were so overwhelmingly superior that one tends to blame the Persian commanders for the startling lack of success. The initiative for both enterprises came from the Great Kings themselves and there seems to have been no question of any significant “power behind the throne”. Yet there is nothing particularly blame-worthy in their conduct of the two operations – apart from the undertaking itself. There comes a time in the history of every empire when expansion has gone far enough and stability and consolidation, if not retrenchment, are needed. The handful of Athenian and Eretrian ships that had abetted the Ionian revolt was a poor pretext for such a massive military and naval effort.
If we turn to Aeschylus’ play, we find some contrast between the characters of Darius and Xerxes. The Persae presents the story of Xerxes’ crest-fallen return to Persia after his defeat at Salamis. Darius’ ghost appears and denounces the folly which has led to the recent débâcle. Darius is stern and dignified; in contrast, Xerxes is petulant and ineffective. At first sight, Herodotus’ narrative might seem to confirm this estimate. One recalls the incident when high winds destroyed the first bridge which Xerxes had constructed over the Hellespont, whereupon Xerxes ordered that the rebellious waters should be whipped as a punishment for the outrage. But perhaps this was not mere childishness on his part. In his multinational host there were many simple tribesmen who knew nothing of the enlightened Zoroastrian religion of the Persians; thus, to restore morale, it was no doubt necessary to demonstrate that even the gods of the winds and the waves were subject to the Great Kings of Persia.
Again, we are inclined to regard Xerxes’ return to Susa, his remote capital, after the disaster of Salamis, as weak and cowardly. Mardonius, his general, seems to have been left callously to his fate in Greece. But the matter may be viewed quite differently. The success of the Persian kings lay very largely in their ability to delegate power. Cyrus, when he conquered Lydia, had delegated the completion of his conquest to his general Harpagus, and probably Mardonius was expected to complete the conquest of Greece in the same way. However, when all has been said, the delineation of character in Aeschylus’ play should not be lightly dismissed. Aeschylus was, after all, writing at a time very close to the events which he described and he cannot altogether have overlooked the reputations which Darius and Xerxes had earned for themselves among their contemporaries.
As for Mardonius, he was Darius’ son-in-law, and had commanded the Persian fleet when it met with disaster on the rocks off Mount Athos. Darius’ dissatisfaction with him is clear, for in the subsequent expedition which that monarch launched against Greece, Mardonius was not in command. Datis and Artaphernes were in charge of the fleet which sailed across the central Aegean to Eretria and Marathon. However, Mardonius was a man of no mean ability and his later reinstatement proves that he enjoyed Xerxes’ confidence. After Xerxes’ return to Persia, Mardonius tried by sensible diplomacy to divide the Greek states against one another before deciding to engage in battle with them. His chances of success in this diplomatic initiative were very good and with a little more perseverance he might have succeeded. But, cut off from supplies by sea, he perhaps had difficulty in feeding his large army and was accordingly under pressure to reach a decision with the utmost possible speed.
The Persian Fleet
No one who reads Herodotus’ narrative can underestimate the importance of the naval factor in the two Persian invasions. The Persians were an inland power and possessed no fleet of their own. It says all the more for the organizing ability of the Great Kings – Xerxes in particular – that they were able to muster such vast armadas. It also suggests that their knowledge of Greek seamanship and fighting power was such that they by no means despised the enemy with whom they had to deal.
The largest contingent of the Persian fleet consisted of Phoenician vessels, manned by Phoenician crews. Rather surprisingly, the Persians relied also upon ships and crews from the Greek Ionian cities which they had subjugated. Inevitably, they must have felt some doubts about the loyalty of the Greek contingents of their own fleet. On several occasions during the campaigns, the Ionian effort seems to have been half-hearted, and at the battle of Mycale the Ionian Greeks at last deserted their Persian overlords to aid their compatriots.
Artemisia, the Greek princess who ruled Halicarnassus (subject to Persian goodwill), was present herself on shipboard at the battle of Salamis, fighting on the Persian side. However, she seems to have joined either fleet as circumstances dictated at any particular moment, for when pursued by an Athenian vessel she deliberately rammed and sank another galley of her own contingent. The Athenians, thinking that she had changed sides, abandoned the pursuit and Artemisia made good her escape without further impediment.
The truth is possibly that Xerxes found it less risky to take the Ionian fleet with him than to leave it in his rear. On every ship there was a force of soldiers, either Persians, Medes or others whose loyalty was to be trusted. Persian commanders often took the place of local captains and Xerxes probably kept the leaders of the subject communities under his personal surveillance. Their position closely resembled that of hostages to the Persians.
Apart from the Phoenician and Greek naval contingents, there was in Xerxes’ fleet an Egyptian squadron which was to distinguish itself in the course of the fighting. We hear also of ships from Cyprus and Cilicia. Cyprus contained both Greek and Phoenician cities and the people of Cilicia were largely of Greek extraction. Whether the Cilicians felt any bond of sympathy with the Greeks of the mainland is another question, but only the links of empire united them with the Persians. The proportion of the total naval strength to that of the land army is recorded: the land forces, when counted by Xerxes at Doriscus in Thrace, were, according to Herodotus, 1,700,000 strong: the strength of the fleet is given with some precision as 1,207 vessels, not including transports.
Persian Naval Strategy
It is interesting that Xerxes reverted to his father’s original plan and decided to invade Greece from the north. He must have considered that his channel through the Athos peninsula eliminated the main hazard of this route. Clearly, he could deploy a much larger army in Greece if his land forces could make their own way along the coast. At the same time, the fleet keeping pace on the army’s flank contained transports which considerably eased his supply problem. The land forces carried a good deal of their own baggage and equipment with the help of camels and other beasts of burden. These did not include horses. It was not customary in the ancient world to use horses for such purposes and it is noteworthy that Xerxes transported his horses by sea on special ships. Horseshoes were unknown in the ancient centres of civilization, and it is possible that the Persian cavalry might have reached Greece with lame mounts if their horses had been obliged to make the whole journey by land.
Warships were, of course, necessary to protect both the transports and the land forces. Without naval defence, the Persian army would have been exposed to the danger of Greek amphibious attacks on its flank and its rear. Moreover, it was Xerxes’ hope that he would crush any Greek naval units immediately, wherever he met them.
He met them first at Artemisium, on the northern promontory of Euboea. Several actions were fought there, with varying outcome. The Greek position was well chosen. In the narrow channel between the Euboean coast and the mainland, the Greeks could not be enveloped by superior numbers. At the same time, they guarded the flank of Leonidas’ forces at Thermopylae. If the Persians sailed round Euboea to attack them in the rear, then the Persian land forces would be separated from their seaborne support. What took the Greeks by surprise was the enormous size of Xerxes’ force, which despite all reports far exceeded their most pessimistic estimates. It was possible for Xerxes to send one section of his fleet round the south of Euboea while he engaged the Greeks at Artemisium with the remainder. Such a manoeuvre entailed no loss of numerical superiority on either front. But summer storms gathered over Thessaly and aided the Greeks. The very size of Xerxes’ fleet meant that there were not sufficient safe harbours to accommodate all the ships; a considerable part of it had to lie well out to sea in rough weather. In this way many ships were wrecked. When a squadron was dispatched to round Euboea and sail up the Ruripus strait, which divides the long island from the mainland, this contingent also fell victim to storms and treacherous currents. The task assigned to it was never carried out.
Quite apart from the figures given by Herodotus, events themselves testify to the huge size of the Persian armada. Despite the heavy losses suffered at Artemisium, Xerxes’ fleet still enjoyed the advantage of dauntingly superior numbers when, late in the same season, the battle of Salamis was fought. Even after Salamis, the number of surviving ships and crews was such that the Greek fleet at Mycale hesitated long before attacking them.
Communication Networks – The Royal Road
Reliable and efficient communications throughout the Empire were a necessary component for its success. The construction, maintenance, and guarding of an extensive network of roads and bridges required a great deal of engineering expertise, manpower, and expense. The Persians adopted and adapted their predecessors’ systems, and greatly expanded them, to facilitate communication across vast distances. Individuals or groups on state business carried sealed documents that allowed access to supplies or provisions en route to their destination.
The most famous of these roads, though it was only one of many, was what Herodotus called the Royal Road from Susa in Elam to Sardis in Lydia (5.52–53). Any “royal” road would have, in fact, run through Persepolis and points eastward, so Herodotus’ terminology reflects a Greek view, which usually viewed Susa as the main Achaemenid capital. From the west it ran through Cappadocia and Cilicia in Anatolia to Armenia and then south through Arbela – along the Tigris River – and on toward Susa. Herodotus notes that there were 111 royal staging posts interspersed on it and mentions several of them specifically (5.52). By his calculations this route ran roughly 1,500 miles and took a journey of ninety days. That was for a traveler in no great haste. Royal dispatches could move with surprising speed, a relay system with fresh horses and messengers at each staging post. Herodotus also describes these royal messengers: “There is nothing mortal that travels faster than these messengers … for as many days as the whole route there are horses and men stationed, one horse and one man set for each day. Neither snow, nor rain, nor heat, nor night hinders them from accomplishing the course laid before them as quickly as possible. After the first one finishes his route, he delivers the instructed message to the second, the second does likewise to the third; from there in rapid succession down the line the message moves.” (8.98)
There were similar routes in all directions from the Empire’s core in Fars.11 Ctesias alludes to other roads running from Mesopotamia and Persia proper to Central Asia. The primary route to Bactria across northern Iran is called in modern works either the (Great) Khorasan Road or, for later periods, by its better known appellation the Silk Road. Administrative documents from Persepolis, Syro-Palestine, and Egypt record disbursements to travelers in all directions. From the Persepolis documentation we gain a sense of the itineraries of a number of the network of roads running between Susa and Persepolis. An Aramaic document tracks travelers journeying from northern Mesopotamia to Damascus and on into Egypt, with several stops along the way listed by name.
Large work crews were involved in the construction and maintenance of these roads. Herodotus’ account of Xerxes’ invasion of Greece describes roadmakers at work, not infrequently the army on campaign. The main roads, constructed wide enough to allow chariots or wagons to travel on them, served to move military forces quickly, but they were also used by travelers or merchants to transport cargo. Roads also at times had to cross obstacles such as rivers. Some permanent bridges, such as one spanning the Halys River in Anatolia, were guarded by a fort. Pontoon bridges allowed crossing of other rivers, for example, at many spots on the northern Tigris and the Euphrates Rivers and their tributaries. Temporary pontoon bridges afforded the means for Persian armies to cross into Europe: Darius I over the Bosporus on his campaign against the Scythians and Xerxes’ bridge over the Hellespont against the Greeks. Of course, rivers and larger waterways were sometimes part of the route. Diodorus Siculus (14.81.4) records a journey on a well-known route at sea along the coast of Cilicia, on land from northwestern Syria to the Euphrates, then down the river to Babylon. Similar sea trading routes connected other parts of the Empire to the core, such as through the Persian Gulf and along the southern coast of Iran to the Indus Valley.