Great reliance had been placed by the Persian king on the effects of the scythe-bearing chariots. It was designed to launch these against the Macedonian phalanx, and to follow them up by a heavy charge of cavalry, which it was hoped would find the ranks of the spearmen disordered by the rush of the chariots, and easily destroy this most formidable part of Alexander's force. In front, therefore, of the Persian centre, where Darius took his station, and which it was supposed the phalanx would attack, the ground had been carefully levelled and smoothed, so as to allow the chariots to charge over it with their full sweep and speed. As the Macedonian army approached the Persian, Alexander found that the front of his whole line barely equalled the front of the Persian centre, so that he was outflanked on his right by the entire left; wing of the enemy, and by their entire right wing on his left. His tactics were to assail some one point of the hostile army, and gain a decisive advantage; while he refused, as far as possible, the encounter along the rest of the line. He therefore inclined his order of march to the right so as to enable his right wing and centre to come into collision with the enemy on as favourable terms as possible though the manoeuvre might in some respects compromise his left.
The effect of this oblique movement was to bring the phalanx and his own wing nearly beyond the limits of the ground which the Persians had prepared for the operations of the chariots; and Darius, fearing to lose the benefit of this arm against the most important parts of the Macedonian force, ordered the Scythian and Bactrian cavalry, who were drawn up on his extreme left, to charge round upon Alexander's right wing, and check its further lateral progress. Against these assailants Alexander sent from his second line Menidas's cavalry. As these proved too few to make head against the enemy, he ordered Ariston also from the second line with his light horse, and Cleander with his foot, in support of Menidas. The Bactrians and Scythians now began to give way, but Darius reinforced them by the mass of Bactrian cavalry from his main line, and an obstinate cavalry fight now took place. The Bactrians and Scythians were numerous, and were better armed than the horseman under Menidas and Ariston; and the loss at first was heaviest on the Macedonian side. But still the European cavalry stood the charge of the Asiatics, and at last, by their superior discipline, and by acting in squadrons that supported each other, instead of fighting in a confused mass like the barbarians, the Macedonians broke their adversaries, and drove them off the field. [The best explanation of this may be found in Napoleon's account of the cavalry fights between the French and the Mamelukes:—"Two Mamelukes were able to make head against three Frenchmen, because they were better armed, better mounted, and better trained; they had two pair of pistols, a blunderbuss, a carbine, a helmet with a vizor, and a coat of mail; they had several horses, and several attendants on foot. One hundred cuirassiers, however were not afraid of one hundred Mamelukes; three hundred could beat; an equal number, and one thousand could easily put to the rout fifteen hundred, so great is the influence of tactics, order, and evolutions! Leclerc and Lasalle presented their men to the Mamelukes in several lines. When the Arabs were on the point of overwhelming the first, the second came to its assistance on the right and left; the Mamelukes then halted and wheeled, in order to turn the wings of this new line; this moment was always seized upon to charge them, and they were uniformly broken."—MONTHOLON'S HISTORY OF THE CAPTIVITY OF NAPOLEON, iv. 70.]
Darius, now directed the scythe-armed chariots to be driven against Alexander's horse-guards and the phalanx; and these formidable vehicles were accordingly sent rattling across the plain, against the Macedonian line. When we remember the alarm which the war-chariots of the Britons created among Caesar's legions, we shall not be prone to deride this arm of ancient warfare as always useless. The object of the chariots was to create unsteadiness in the ranks against which they were driven, and squadrons of cavalry followed close upon them, to profit by such disorder. But the Asiatic chariots were rendered ineffective at Arbela by the light-armed troops whom Alexander had specially appointed for the service, and who, wounding the horses and drivers with their missile weapons, and running alongside so as to cut the traces or seize the reins, marred the intended charge; and the few chariots that reached the phalanx passed harmlessly through the intervals which the spearmen opened for them, and were easily captured in the rear.
A mass of the Asiatic cavalry was now, for the second time, collected against Alexander's extreme right, and moved round it, with the view of gaining the flank of his army. At the critical moment, Aretes, with his horsemen from Alexander's second line, dashed on the Persian squadrons when their own flanks were exposed by this evolution. While Alexander thus met and baffled all the flanking attacks of the enemy with troops brought up from his second line, he kept his own horse-guards and the rest of the front line of his wing fresh, and ready to take advantage of the first opportunity for striking a decisive blow. This soon came. A large body of horse, who were posted on the Persian left wing nearest to the centre, quitted their station, and rode off to help their comrades in the cavalry fight that still was going on at the extreme right of Alexander's wing against the detachments from his second line. This made a huge gap in the Persian array, and into this space Alexander instantly dashed with his guard; and then pressing towards his left, he soon began to make havoc in the left flank of the Persian centre. The shield-bearing infantry now charged also among the reeling masses of the Asiatics; and five of the brigades of the phalanx, with the irresistible might of their sarissas, bore down the Greek mercenaries of Darius, and dug their way through the Persian centre. In the early part of the battle, Darius had showed skill and energy; and he now for some time encouraged his men, by voice and example, to keep firm. But the lances of Alexander's cavalry, and the pikes of the phalanx now gleamed nearer and nearer to him. His charioteer was struck down by a javelin at his side; and at last Darius's nerve failed him; and, descending from his chariot, he mounted on a fleet horse and galloped from the plain, regardless of the state of the battle in other parts of the field, where matters were going on much more favourably for his cause, and where his presence might have done much towards gaining a victory.
Alexander's operations with his right and centre had exposed his left to an immensely preponderating force of the enemy. Parmenio kept out of action as long as possible; but Mazaeus, who commanded the Persian right wing, advanced against him, completely outflanked him, and pressed him severely with reiterated charges by superior numbers. Seeing the distress of Parmenio's wing, Simmias, who commanded the sixth brigade of the phalanx, which was next to the left wing, did not advance with the other brigades in the great charge upon the Persian centre, but kept back to cover Parmenio's troops on their right flank; as otherwise they would have been completely surrounded and cut off from the rest of the Macedonian army. By so doing, Simmias had unavoidably opened a gap in the Macedonian left centre; and a large column of Indian and Persian horse, from the Persian right centre, had galloped forward through this interval, and right through the troops of the Macedonian second line. Instead of then wheeling round upon Sarmenio, or upon the rear of Alexander's conquering wing, the Indian and Persian cavalry rode straight on to the Macedonian camp, overpowered the Thracians who were left in charge of it, and began to plunder. This was stopped by the phalangite troops of the second line, who, after the enemy's horsemen had rushed by them, faced about, countermarched upon the camp, killed many of the Indians and Persians in the act of plundering, and forced the rest to ride off again. Just at this crisis, Alexander had been recalled from his pursuit of Darius, by tidings of the distress of Parmenio, and of his inability to bear up any longer against the hot attacks of Mazaeus. Taking his horse-guards with him, Alexander rode towards the part of the field where his left wing was fighting; but on his way thither he encountered the Persian and Indian cavalry, on their return from his camp.
These men now saw that their only chance of safety was to cut their way through; and in one huge column they charged desperately upon the Macedonians. There was here a close hand-to-hand fight, which lasted some time, and sixty of the royal horse-guards fell, and three generals, who fought close to Alexander's side, were wounded. At length the Macedonian, discipline and valour again prevailed, and a large number of the Persian and Indian horsemen were cut down; some few only succeeded in breaking through and riding away. Relieved of these obstinate enemies, Alexander again formed his horse-guards, and led them towards Parmenio; but by this time that general also was victorious. Probably the news of Darius's flight had reached Mazaeus, and had damped the ardour of the Persian right wing; while the tidings of their comrades' success must have proportionally encouraged the Macedonian forces under Parmenio. His Thessalian cavalry particularly distinguished themselves by their gallantry and persevering good conduct; and by the time that Alexander had ridden up to Parmenio, the whole Persian army was in full flight from the field.
It was of the deepest importance to Alexander to secure the person of Darius, and he now urged on the pursuit. The river Lycus was between the field of battle and the city of Arbela, whither the fugitives directed their course, and the passage of this river was even more destructive to the Persians than the swords and spears of the Macedonians had been in the engagement. [I purposely omit any statement of the loss in the battle. There is a palpable error of the transcribers in the numbers which we find in our present manuscripts of Arrian; and Curtius is of no authority.] The narrow bridge was soon choked up by the flying thousands who rushed towards it, and vast numbers of the Persians threw themselves, or were hurried by others, into the rapid stream, and perished in its waters. Darius had crossed it, and had ridden on through Arbela without halting. Alexander reached that city on the next day, and made himself master of all Darius's treasure and stores; but the Persian king unfortunately for himself, had fled too fast for his conqueror: he had only escaped to perish by the treachery of his Bactrian satrap, Bessus.
A few days after the battle Alexander entered Babylon, "the oldest seat of earthly empire" then in existence, as its acknowledged lord and master. There were yet some campaigns of his brief and bright career to be accomplished. Central Asia was yet to witness the march of his phalanx. He was yet to effect that conquest of Affghanistan in which England since has failed. His generalship, as well as his valour, were yet to be signalised on the banks of the Hydaspes, and the field of Chillianwallah; and he was yet to precede the Queen of England in annexing the Punjaub to the dominions of an European sovereign. But the crisis of his career was reached; the great object of his mission was accomplished; and the ancient Persian empire, which once menaced all the nations of the earth with subjection, was irreparably crushed, when Alexander had won his crowning victory at Arbela.
SYNOPSIS OF EVENTS BETWEEN THE BATTLE OF ARBELA AND THE BATTLE OF THE METAURUS.
B.C. 330. The Lacedaemonians endeavour to create a rising in Greece against the Macedonian power; they are defeated by Antipater, Alexander's viceroy; and their king, Agis, falls in the battle.