There are times when normally competent military commanders are truly outmatched by the opponents they encounter. There is no doubt that this is the case for Darius III, who was soundly defeated at the hands of the military prodigy, Alexander of Macedon. His defeat sounded the end of Persia as a globe spanning and dominant empire. Appearing primarily in Greek written texts, Darius has inevitably been presented through the ages in a negative light, yet there is strong evidence at least for his stalwart courage. As a young man he distinguished himself in single combat against a Champion sent forward by an Iranian mountain tribe in rebellion against the Persian Empire.
His route to the Persian throne was difficult and winding, for he was only a minor noble of the royal family, posted far away from the center of the empire as Governor of Armenia. A series of traitorous poisonings engineered by the palace court wiped out the majority of the ruling elite, paving the road to his Imperial rule in 336 B.C.E.
When Alexander initially invaded the Anatolian Empire in 334 B.C.E., Darius could be excused for treating this as a local difficulty to be handled by the regional governors. When he eventually did respond to the invasion and advanced with his army into Syria in 333 B.C.E., he seemed to have outmaneuvered Alexander into a disadvantageous position. Darius converged behind the Macedonians on the coastal plain. There he gathered his army into a strong defensive position, then tried an outflanking move – tactics that might have succeeded against a lesser opponent. The Persian forces were quickly shattered by Macedonian cavalry, however, and Darius was forced to flee the battlefield to avoid capture and greater losses. Darius’s second great battle against Alexander proved to be just as disastrous. Fleeing back to the city of Ecbatana, Darius intended to raise another army to continue the fight, but a rebellious subordinate governor captured him, held him prisoner for a time, and finally killed him.
Alexander the Great vs Darius III
After his humiliating defeat at the hands of Alexander in 333 B.C.E., the Persian ruler Darius III, was resolute in his decision to fight the Macedonians again and crush them. He assembled a considerable army by calling upon tribute and reserves from his Asian provinces, and then waited in Mesopotamia for Alexander to come to him. In the summer of 331 BC, Alexander – equally eager for yet another clash – marched from Egypt through Syria to the Euphrates River. Darius used the quickness of his cavalry to deny them supplies and shelter in the Euphrates valley, forcing Alexander to continue marching his army northeast to the Tigris River. Darius waited patiently for his rival Alexander’s much smaller army on the far side of the river.
Alexander crossed the Tigris unaware of the disposition or strength of Darius’s gathered army. After four days of marching along the river, Alexander managed to take prisoners in a clash with Persian cavalry. Interrogation revealed that Darius was waiting with his army on a plain some 6 miles away, using intervening hills to block line of sight. Alexander fortified his own camp and then spent four days preparing for the battle to come. Late on the evening of September 29, he advanced his army en masse toward Guagamela with the intent of attacking at dawn after the night march. After finally reaching the crest of the hill above the Persian camp on the plain below, Alexander ordered his army to halt. After beholding the full scale of his enemy Darius’s army, Alexander decided to wait. The following day, he surveyed the battlefield and finalized his battle plan. After deciding against the night attack, he made adjustments to his usual battle dispositions – his infantry phalanx would remain in the center, the companion cavalry would gather on the right, supported by a light cavalry left-wing. He also prepared measures in case of other possible battlefield developments. On the wings of his army, additional cavalry and skirmishers would be in position to counter any outflanking moves. He also stationed a second line of infantry in the rear of the line of battle, leaving them ready to turn around and defend the backs of the front line. Thus satisfactorily prepared, Alexander slept peacefully through the night. The following morning he marched his eager army down onto the plain of battle, riding as usual at the head of the Macedonian cavalry with the support of the best of his combat infantry. He led his entire army to the right, across the front of the waiting Persian lines. Alexander attacked the Persian left with his cavalry, while the unprepared Persian cavalry attempted outflanking moves but were soundly defeated. Obscured among the chaotic sounds of combat, with large plumes of dust rising from the dryness of the plain, Darius could not see Alexander’s next move. Alexander the Great charged his heavy cavalry – with infantry support – to strike at Darius in the Persian army center. Taken completely by surprise, the Persian king fled. Alexander’s initial instinct was to pursue him, but his horsemen were still needed to aid his other forces engaged in heated combat on other parts of the battlefield. The Persian army was soon scattered after suffering massive casualties. Alexander’s victory was swift and indisputable.
The Persian High Command
The Persian numbers in the two invasions of Greece 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.
In the spring of 336, Philip had sent an advance force of 10,000 Macedonians to AsiaMinor under the command of Parmenion, Attalus, and a certain Amyntas, perhaps the son of Arrhabaeus. Their presence, and the apparent initiation of the war against Persia, induced the Carian satrap Pixodarus to seek an alliance with Philip II, in the expectation of Macedonian success, at least on the coast of Asia Minor. But, by the fall of 336, Philip had been assassinated, Egypt recovered for Persia, and Pixodarus had found a new son-in-law in Orontopates. Indeed, the latter’s position as satrap of Caria suggests that Darius did not trust Pixodarus entirely. For the Macedonians, a window of opportunity had opened and closed. Whether Darius had sent gold to Macedonia to secure Philip’s assassination is unclear: Alexander found it convenient to level the charge against his opponent in 332, knowing that many in his camp and in the Greek world would regard it as plausible, if not dead certain.
Should Darius III have taken measures to preempt Alexander’s invasion? Was he capable of doing so? These are difficult questions to answer. On the one hand, he may have found it difficult to secure a new fleet capable of contesting the crossing of the Hellespont. On the other, he may not have thought it necessary. Perhaps he was encouraged by the poor showing of the advance force, which Memnon had managed to hold in check, and by the reassertion of the pro-Persian element in cities such as Ephesus when the news of Philip’s death became known. News of rebellions in Europe must also have provided grounds for optimism. Certainly, Darius had little reason to assume that the untried Alexander would have much more success than Agesilaus had some sixty years earlier, and he must have believed that the armies of a coalition of satraps from Asia Minor would suffice to repel the invader
It is a common mistake to assume, from hindsight, that Alexander’s conquest of Persia was inevitable or that the satraps and their king must have viewed the Macedonian invasion with deep foreboding. The Persians had learned the value of Greek hoplites, and they had a plentiful supply of them – though as it turned out they were reluctant to use them to maximum effect. Their skilled horsemen by far outnumbered the invader’s cavalry. Only too late would they discover that their own cavalry, armed with javelins and bows, were no match for the “shock tactics” of the dense wedges of Macedonians and Thessalians. But all that was yet to come, with neither side sufficiently experienced in the techniques and weaponry of their opponents.
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.