A great mobilization had been held of the forces from the still unconquered eastern empire. The valuable stiffening of Greek mercenaries had been lost, all but about 4,000. But beside the elite troops of Persia, there were the less disciplined but fierce and tough levies of Bactria and Sogdiana under Bessus, the powerful satrap of Bactria and cousin of the King; also auxiliaries of many tributary races from the Caucasus to the Indian frontier. All were now based on Babylon, where the Persian commanders had worked hard on improving weaponry. After the lesson of Issus, javelins had been replaced with spears; and there was a squadron of the fearsome scythed chariots, with their spearheaded yoke poles and multi-bladed wheels. Nothing, unfortunately, could be done about the continuing liability of Darius as commander-in-chief.
The cavalry under Nabarzanes was of high calibre; born horsemen, and far better mounted than the Greeks. Beside the tall Nisaeans, probably as big as modern chargers, Bucephalas must have looked like a thickset pony. For such troops to wear down the Greeks with harrying tactics promised better results than a pitched battle, even without Darius’ known record. But either he was resolved to redeem the honour lost at Issus, or had been made to feel he ought. He marched his huge host towards the ancient town of Arbela, between the Tigris and the hills.
A cavalry detachment was sent west to the Euphrates, to locate and oppose Alexander’s crossing. But his advance engineers ran out their double bridge on piles from their own side till Alexander came up; the Persians, commanded by Mazaeus, satrap of Babylon, made off without opposing him. Babylon, the heart of ancient conquered Assyria, was not the most loyal part of the Persian empire.
The Tigris, whose name means Arrow, was too swift to bridge and had to be forded. Alexander got his infantry across between two columns of cavalry, one to break the current for them, the other to catch any men swept away. He headed the infantry himself, and then stood on the bank pointing out the shallower places. Not a man was lost.
No other commander of unmechanized forces could ever move as fast as Alexander. He also knew when to take his time. Instead of striking across the hot river plain, where the retreating Mazaeus had burned the crops, he skirted it by the northern uplands, cooler and well watered. Too late to catch him as he struggled across the Tigris, Darius improved the time by sending an army of slaves to level the intervening plain of Gaugamela. He had been told that Issus had been lost because he had not had room to deploy his forces; and the chariots would need smooth ground.
As Alexander marched south towards him east of the Tigris, there was an eclipse of the moon, one of the most alarming phenomena of the ancient world. Thanks to Aristotle, Alexander understood its cause; not for him the fatal delay of the superstitious Nicias which, in the previous century, had lost the whole Athenian force in Sicily and with it the Peloponnesian War. Alexander did not, however, bother his anxious soldiers with astronomy, but summoned the seers to cheer them up by identifying the darkened moon with Persia. He sacrificed punctiliously to the powers involved, the Sun, Moon and Earth; his knowing what they were doing did not affect his belief that they were gods.
A Persian moon had indeed been eclipsed for ever. Stateira, wife of Darius, the most beautiful woman of mortal birth in Asia, had fallen sick and died. Plutarch says, without hint of scandal, that she died in childbirth, in which case it must have been much earlier. In any event, Alexander had held up his march for a day to perform her funeral rites, assuming the duties of a kinsman, including a day-long fast.
He may well have reproached himself, if he had sacrificed her to his sense of theatre. The splendid set piece from Xenophon would never be enacted now. Even in cushioned wagons, journeys over earth roads on hard wheels must have been a tiring business, with exposure to local infections. He must have wished he had been content with a less spectacular piece of generosity, which—since he had never attempted to use the women as hostages—he could have afforded. He had now to witness the grief of the children and Sisygambis; and though her continuing affection shows that she never blamed him, there need be no doubt that his mourning was sincere.
Curtius has a story here, with important later implications. Alexander sent one of the Queen’s attendant eunuchs, who is actually named, to inform Darius of her death and assure him that she had had the customary Persian funeral honours. The scene moves to Darius’ tent, where Darius cries out that such honours must be the tribute to a mistress. The eunuch reassures him, and he then expresses respect for his enemy’s conduct. This episode is the prologue to much inside information from Darius’ headquarters. In Curtius, it has every indication of having been first supplied by an eyewitness; a vivid and lively raconteur with a courtier’s sense of tact. More will be heard before long of such a person.
Darius now sent out scouts to report on the approach of Alexander. He caught a few, and learned where the Persians were. He then gave his men a four-day rest, trusting Darius not to move from his swept and garnished battleground. He also had his own base camp fortified, no doubt remembering the Issus massacre; and left in it all noncombatants, including Queen Sisygambis. He then led his troops towards the plain of Gaugamela. From the low hills that fringed it he saw the vast Persian host, of which the most conservative estimate is 200,000 infantry and 40,000 cavalry. His own numbers were 40,000 infantry and 7,000 horse.
He convened a war council in the style of Macedon, whose kings conferred with their chiefs as primi inter pares. Several commanders were for bringing the rested troops straight into action; which, in view of Persian numbers, says a good deal for their confidence in Alexander. The experienced Parmenion pointed out that this was a field prepared for them by Darius, who might have hidden pit traps and caltrops in their way. Alexander agreed, made camp and rode out to reconnoitre, probably glad of the excuse to pause and calculate, without seeming overimpressed by Persian strength. He took a good look, in full view of their outposts. After noting their immense superiority in cavalry, the arm on which his own tactics most relied, he rode back to think.
Parmenion, who had evidently gone with him, advised him to try a night attack. He answered that he would not “steal a victory”—referring to Xenophon, original coiner of the phrase “to steal a march.” To flourish bravura over shrewdness was part of the Alexander touch. Night operations had endless possibilities of confusion and error; a night pursuit would give routed enemies the chance to re-form and retrieve morale. Darius had been allowed a year in which to collect his remaining assets and put them on the table. Now Alexander meant to beat him at his own game on his chosen pitch, and pick up the stake entire, with unarguable finality. It was the crux of his own destiny, and of much more, and this he knew. He ordered his men a good dinner and told them to get some sleep; they were to set out before dawn. He himself sat up late, thinking and planning.
Darius had been thinking too. As Alexander had hoped, he had been thinking like Parmenion. The Greeks were hopelessly outnumbered; what would they do but try to snatch advantage from a night surprise? Orders went out, not just to the outposts but to the whole huge host, to stand by all night, the men in arms and the horses bridled. To hear was to obey. Night passed, the men grew tired. In Alexander’s tent the lamp went out. Decisions taken, the outcome laid on the gods, he fell into deep sleep. When it was time for the men to be roused and fed, his officers found him sleeping like a child. They gave the necessary orders and came back. Finally Parmenion had to shake him. When asked how he could be so calm, he said he had had far more to worry about when the Persians were burning the crops ahead of him. Now, he had been given his heart’s desire.