It was a bad day for history when Quintus Curtius enrolled at a Roman school of rhetoric. With access to priceless sources now destroyed by fire or sack, of which he gives us tempting glimpses, he makes every major speech in his History a showpiece of his own, which seekers of fact can safely discard unread. In this spirit of academic exercise he furnishes Darius and Alexander with long pre-battle orations, which need not detain us. More interestingly, since it comes from a first-hand source, Arrian describes Alexander’s briefing of his officers. He told them they did not need speeches to inspire them; their own courage and pride in it would do that; just let each encourage the men under his command. They were not fighting now for Asia Minor, or for Egypt, but for the sovereignty of all Asia. Let each keep strict discipline in time of danger; observe complete silence when ordered to advance silently; raise a terrifying battle yell when the right moment came; be alert for orders, and swiftly pass them on. He was thinking ahead to the blinding dust which would prevent all visual signals. He needed to keep his plan flexible, and wanted swift response to any change of tactics.
The instruction to make the war yell terrifying may not be unrelated to the fact that, according to Plutarch, before the battle he sacrificed to Fear. Greeks readily personified any natural force; but there is no other record of his ever honouring this deity. It would seem that since Issus he thought of Fear as Darius’ familiar spirit. All these preparations attended to, he marched his men from the low hills down to the plain, as dawn light revealed the hosts to one another.
The Persian front, with plenty of room to manoeuvre, and outnumbering the Macedonians by about five to one, was so much longer that if things went amiss they stood to be not only outflanked but encircled. Alexander deepened his flanks with reverses which in case of an enveloping movement could turn outward to form a square. Parmenion as usual led the left wing, where he was opposed by the brave and able Mazaeus, whose withdrawal at the Euphrates had certainly not been caused by cowardice. Darius took the royal station in the centre; but had in front of him his Greek mercenaries and other strong contingents; also fifteen elephants and fifty scythed chariots. Alexander led the Macedonian right. Confronting him was the massive army of Bactria, led by its satrap, Bessus. So far did its line overlap his own, that he started the battle nearly opposite Darius.
He began, however, edging out to his right, as if to escape the Persian overlap. Darius ordered a corresponding movement to keep his overlap extended; he still committed no troops to action, trying to divine what Alexander meant to do. He kept moving right, till he was approaching the edge of Darius’ carefully flattened arena. On the rougher ground beyond, scythed chariots would not run and cavalry would be hampered. It was a trial of nerve. Darius, falling to the bluff, ordered Bessus’ men to oppose further rightward movement. Persian troops were now engaged. Alexander, by a series of precisely timed manoeuvres, caused more and more of them to be involved. He himself, at the head of the Companion Cavalry, meticulously bided his time.
He had been located, and Darius ordered the scythed chariots to charge him. But he had been permitted a leisurely reconnaissance beforehand and his arrangements for them were made. They were attacked with missiles by the Agriani; some of the daring tribesmen leaped head on at the horses, dragging them to a halt and pulling down the charioteers. Those that got through met wide lanes in the well-drilled infantry, shot harmlessly past and were disposed of at leisure in the rear.
Meantime, Darius’ left wing was becoming increasingly committed, while Parmenion’s forces still pinned down his right. The centre was thinning. Despite Alexander’s fewer numbers, he had ingeniously contrived that his apex of strength should meet an area of Persian weakness just where he wanted it to be.
It was time to change horses. A squire had been holding ready the veteran Bucephalas, now twenty-four, keeping him fresh for this moment, the climax of his active service. Alexander rode to the head of the royal squadron. Forming it into column, with a tapering point of which he was the apex, he raised the war yell, and hurtled towards Darius, now in the front line. The cavalry had not forgotten their orders to make a terrifying noise; they thundered after, offering their tributes to Fear.
Fear was their friend. As, unimpeded by the fifteen elephants, they rolled up the Persian front and approached the royal chariot, Darius wheeled it round, snatching the reins dropped by its wounded driver, and was the first to fly. The fall of the charioteer had been seen by neighbouring Persians; the chariot’s flight convinced them that it was the King who had fallen and died. The centre disintegrated; a signal for general rout. Alexander and his cavalry crashed on, hewing their way in pursuit, and intent on catching Darius.
A message then arrived from Parmenion that his sector was still heavily engaged. Alexander was no Rupert of the Rhine; once the messenger had located him in the dust and confusion, he abandoned the tempting chase to support his men and consolidate his victory. While reaching the threatened point he fought a fierce engagement in which sixty Companions died and Hephaestion was wounded. Much dispute has raged over this message, and on whether it was later stressed by Alexander’s chroniclers to discredit Parmenion. Its propaganda value seems very doubtful, considering that Parmenion’s was a holding operation, competently fulfilled, and the message saved Alexander from the grave danger of leaving a doubtful field. He was no doubt anxious to tell the world why he had let Darius slip through his fingers, and to receive proper credit for rescuing his left wing (whose danger was over by the time he got there); but this is a long way from finding scapegoats, and Parmenion emerges from the account without discredit.
As it was, Alexander’s forward dash had left a small gap in the line, not of strategic size, but big enough for a small task force detailed by Darius to attempt the rescue of his family. This troop of Royal Guards and Indians got through, and penetrated as far as the base camp, where they wasted valuable time in looting, and in killing non-combatants, before they reached their objective. Diodorus relates that many Persian captives joined forces with their countrymen and prepared for an escape; but that the Queen Mother Sisygambis, when the women called to her to hurry, sat silent and immobile in her chair. Soon afterwards the Persian troop was beaten off.
Meantime the satrap Mazaeus had learned of Darius’ flight. Like Nabarzanes at Issus, who had also held down the redoubtable Parmenion and been similarly left in the lurch, he decided his obligations were at an end. He extricated as many of his men as he could, and went racing back to Babylon. Though he and Nabarzanes had reached the same conclusion, they were different men; each would act as his nature prompted him.
Alexander, finding Parmenion’s force already out of trouble, dashed off with the Companions, still hoping to catch Darius on his way to his base at Arbela. So furious was the race that a thousand horses foundered. (Not Bucephalas. Alexander had taken time to have him cared for. The old horse, never used again in battle, was to be cherished for six more years.) At Arbela it was proved that the horses had died in vain; once more the Great King’s chariot was found abandoned, along with whatever could not be carried away in the headlong Persian flight; this must have included a good many women. Alexander paused, to rest his men and consider his objective. Hitherto, he had accorded Darius much the same military importance as himself. At Arbela he decided that the capture was, after all, a very low priority. So completely did he discard the pursuit in favour of other aims, so open was his contempt for Darius as an enemy, that it would have been inconsistent to put much importance on Parmenion’s responsibility, if any, for letting him slip away.