Alexander having completed his preparations, and appointed Antipater to act as regent of Macedonia during his absence, crossed over the Hellespont into Asia in the spring of 334 B.C. His army, though numerically insignificant when compared with the magnitude of the enterprise which lay before it, proved nevertheless, from the physical superiority, courage, and daring of the men, combined with the perfection of their organisation and discipline, and the consummate skill of their leader, more than a match for any force, however numerous, which was brought into the field against it. We may here quote a passage from Thirlwall, in which he describes the composition, organisation, and equipment of this heroic little army which performed the greatest deeds recorded in military annals:
“The main body, the phalanx—or quadruple phalanx, as it was sometimes called, to mark that it was formed of four divisions, each bearing the same name—presented a mass of 18,000 men, which was distributed, at least by Alexander, into six brigades of 3000 each, formidable in its aspect, and on ground suited to its operations, irresistible in its attacks. The phalangite soldier wore the usual defensive armour of the Greek heavy infantry—helmet, breast-plate, and greaves: and almost the whole front of his person was covered with the long shield called the aspis. His weapons were a sword long enough to enable a man in the second rank to reach an enemy who had come to close quarters with the comrade who stood before him, and the celebrated spear, known by the Macedonian name, sarissa, four-and-twenty feet long. The sarissa, when couched, projected eighteen feet in front of the soldier: and the space between the ranks was such that those of the second rank were fifteen, those of the third twelve, those of the fourth nine, those of the fifth six, and those of the sixth three feet in advance of the first line: so that the man at the head of the file was guarded on each side by the points of six spears. The ordinary depth of the phalanx was of sixteen ranks. The men who stood too far behind to use their sarissas, and who therefore kept them raised until they advanced to fill a vacant place, still added to the pressure of the mass. As the efficacy of the phalanx depended on its compactness, and this again on the uniformity of its movements, the greatest care was taken to select the best soldiers for the foremost and hindmost ranks—the frames, as it were, of the engine. The bulk and core of the phalanx consisted of Macedonians; but it was composed in part of foreign troops. These were no doubt Greeks. But the northern Illyrians, Paeonians, Agrianians, and Thracians, who were skilled in the use of missiles, furnished bowmen, dartsmen, and slingers: probably according to the proportion which the master of tactics deemed the most eligible, about half the number of the phalanx. To these was added another class of infantry, peculiar in some respects to the Macedonian army, though the invention belonged to Iphicrates. They were called Hypaspists, because, like the phalangites, they carried the long shield: but their spears were shorter, their swords longer, their armour lighter. They were thus prepared for more rapid movements, and did not so much depend on the nature of the ground. They formed a corps of about 6000 men. The cavalry was similarly distinguished into three classes by its arms, accoutrements, and mode of warfare. Its main strength consisted in 1500 Macedonian and as many Thessalian horse. But the rider and his horse were cased in armour, and his weapons seem to have corresponded to those of the heavy infantry. The light cavalry, chiefly used for skirmishing and pursuit, and in part armed with the sarissa, was drawn from the Thracians and Paeonians, and was about the third of the number of the heavy horse. A smaller body of Greek cavalry probably stood in nearly the same relation to the other two divisions, as the Hypaspists to the heavy and light infantry. To the Hypaspists belonged the royal foot bodyguard, the Agêma, or royal escort, and the Argyraspides, so called from the silver ornaments with which their long shields were enriched. But the precise relation in which these bodies stood to each other does not appear very distinctly from the descriptions of the ancients. The royal horse-guard was composed of eight Macedonian squadrons, filled with the sons of the best families. The numbers of each are not ascertained, but they seem in all not much to have exceeded or fallen short of a thousand.”
From this description of the Macedonian army, it may easily be imagined what a formidable aspect its main arm—the phalanx of panoplied infantry—would present to the enemy. Polybios informs us that the Roman officers who were present in the battle of Kynoskephalai, and then saw the phalanx for the first time, told him that in all their experience of war they had never seen anything so terrible. The phalanx, however, as that historian points out, could only operate effectively on level and open ground—was quite unfit for rapid advance and rough terrain, and useless if its ranks were broken. It was thus helpless in face of an active enemy unless well supported by cavalry and light troops. This explains why Alexander attached so much importance to his cavalry. In point of fact he owed none of his victories to the phalanx; his cavalry, rapid in its evolutions and charging with resistless impetuosity, gained them all. In addition to the troops which have been particularised in the extract, there was one kind organised by Alexander called dimachai, intermediate between cavalry and infantry, being designed to fight on horseback or on foot as circumstances required. His artillery formed a very useful part of his equipment. The balistai and katapeltai of which it consisted threw stones and darts to the distance of 300 yards, and was frequently employed with great effect.
As he foresaw that in the course of his expedition he was likely to penetrate to regions either imperfectly or altogether unknown, he entertained on his staff men of literary and scientific requirements to write his deeds, and describe those countries and nations to which he might carry his arms.
He first came into conflict with the Persians on the banks of the Granîkos, a small river, which, flowing from Mount Ida through the Trojan plain, enters the Propontis to the west of Kyzikos. Their army, which consisted of 20,000 horse, and an equal number of Greek mercenaries, was commanded by several satraps who were assisted by the counsels of Memnon the Rhodian, the ablest general in the service of Darius. The Persians were drawn up in line along the right bank of the stream, while their mercenaries were posted on a range of heights that rose in the rear. Alexander drew up his forces on the opposite bank in the order which he adopted in all his great battles. Thus the phalanx formed his centre; he commanded himself the extreme right, and the officer in whom he had most confidence the extreme left. To either wing were attached such brigades of the phalanx as circumstances seemed to require. The Persians having observed where Alexander was posted, strengthened their left wing with dense squadrons of their best cavalry, anticipating that this part of their line would be exposed to the first fury of the onset led by himself in person. They judged aright. Alexander having sent a detachment of cavalry across the stream, followed with other cavalry and a portion of the phalanx. The Persians made a gallant resistance, but were soon beaten. Their darts and scimitars were no match for the tough cornel of the Macedonian spears. Their ranks first broke where Alexander himself in the hottest of the fight was dealing death and wounds around him. A blow which was descending on his own head, and which if delivered would have proved fatal, was intercepted by Kleitos, who cut off the arm of the assailant, scimitar and all. The field was won before either the phalanx on the one side, or the Greek mercenaries on the other, could come into action. The Macedonians, after returning from a short pursuit, closed around the mercenaries and cut them down, all but 2000 who were made prisoners and sent in chains to Macedonia. The number of the Persians slain was about 1000 against only 115 on the other side.
Alexander did not, like most other conquerors after a victory, plunder the surrounding country, but regarding Asia as already his own, treated the inhabitants as subjects whose interests he was bound to protect and promote. Neither did he at once advance into the interior, but, acting by a rule of strategy which he was always careful to observe, resolved to make his rear secure. He therefore first reduced all the western provinces of the empire which Darius after the defeat of his satraps had placed under the supreme authority of Memnon the Rhodian. Memnon was a formidable antagonist, both from his skill in war, and from his having a powerful fleet at his command, which gave him the dominion of the sea, and enabled him to threaten at will the shores of Greece and Macedonia.
Alexander marched from the battle-field to Ilion, and advanced thence southward through the beautiful regions of Ionia and the other maritime states, which, in striking contrast to their present blighted condition, were then at the height of prosperity—adorned with numerous rich and splendid cities, which vied with each other in all the arts of refinement. The terror of his name preceded him, and these cities one after another, including even Sardis, the western capital, which was strongly fortified, threw open their gates to admit him. Milêtos, however, and Halikarnassos, being supported by the Persian fleet, refused to surrender, and did not fall into his hands until each had been for some time besieged. After the fall of Halikarnassos, the rest of Karia, of which it was the capital, submitted, and then the operations of the first year of the war were brought to a close by the reduction of all Lykia. In this province he gave his army some rest.
The next campaign opened with the conquest of Pamphylia, after which Alexander turned his march away from the coast with a view to invade Phrygia, which lay to the north beyond the lofty range of Tauros. It was now the depth of winter, but Alexander in defiance of all obstacles—frost and snow, torrents and precipices, and the resistance of the fierce Pisidian mountaineers—forced his way into the Phrygian plains. This passage of the Tauros at such a season was an achievement not unworthy to rank with the more celebrated passage of the Alps made by Hannibal about a century later. After he had cleared the defiles, a march of five days brought him to Kelainai, the capital of the greater Phrygia, which was pleasantly situated where the river Marsyas joins the Maeander, and was embellished with a palace and a royal park. Alexander, deeming its acropolis to be impregnable, made terms with the inhabitants, and then advanced to the ancient capital called Gordion, after Gordios, the father of the celebrated Midas, the first king of the country. Here was the complicated knot to which the prophecy was attached that whoever untied it should be Lord of Asia. It was tied on a rope of bark which fastened the yoke to the pole of the wagon on which Midas had been carried into the city on the day when the people chose him as their king. Alexander either undid the knot or cut it through with his sword.
On the return of spring he moved forward to Ankyra (now Angora), and there had the satisfaction to receive the submission of the Paphlagonians, who at that time were a very powerful nation. Being thus free to move southwards without leaving an enemy in his rear, he entered Kappadokia, and having overrun it without encountering any serious opposition, he recrossed the Tauros by a pass that admitted him into the fertile plains of Eastern Kilikia. The capital of this province was Tarsos, a flourishing seat of commerce, art, and learning, built on both banks of the river Kydnos, which was navigable to the sea. This important city fell without resistance into Alexander’s hands, the satrap having fled at the tidings of his approach. Here, however, he nearly lost his life, having caught a violent fever by throwing himself when heated into the waters of the Kydnos, which ran cold with the snows of Mount Tauros. After his recovery he sent Parmeniôn eastward to occupy the passes leading into Syria, called the Syrian Gates, and marched himself in the opposite direction to reduce the hill-tribes of Western Kilikia. In the meantime Darius, advancing from the East, had crossed the Euphrates and the Syrian desert at the head of an army not less numerous than that with which Napoleon invaded Russia, and was lying encamped on a wide plain suitable for his cavalry within a two days’ march of the Syrian Gates. Here he waited for some time ready to fall upon the Macedonian troops and crush them with the overwhelming superiority of his numbers when they debouched from the defile. When he despaired of their coming, he marched into Kilikia through a pass known as the Amanian Gates and encamped on the banks of the Pinaros which flows through the plain of Issos to the sea. He thus placed himself in a trap where he was hemmed in by the mountains and the sea in a narrow plain not more than a mile and a half in width. Alexander meanwhile had passed through the other gates into the Syrian plain when he learned to his astonishment that Darius was now in his rear. He at once retraced his steps, and by midnight regained the pass, where from one of its summits he beheld the Persian watchfires gleaming far and wide over the plain of Issos. At daybreak he marched down the pass, and on reaching the open part of the plain made the usual disposition of his forces, Parmeniôn commanding the left, and himself the right wing. Darius had drawn up his line, which extended from the mountains to the sea, along the northern bank of the river Pinaros. In the centre, which confronted the dreaded Macedonian phalanx, he had posted a body of 30,000 heavy-armed Greek mercenaries.
Alexander began the action by dislodging a detachment of the enemy which had been posted at the base of the mountains and threatened his rear. Finding the Persians did not advance, he crossed the river and charged their left wing with such impetuosity that he broke their ranks and swept them from the field irretrievably discomfited. He then wheeled round and brought timely succour to his phalanx, which the Greek mercenaries of Darius were driving back with disordered ranks to the river. The struggle now became desperate, for these mercenaries, bitterly resenting the state of political degradation to which the Macedonians had reduced their compatriots in southern Greece, now fought against them with all the fury that the passions of hate and rivalry could inspire. They were nevertheless driven back, and the tide of battle surged up towards the state chariot itself, on which Darius was mounted in the centre of his line. The pusillanimous monarch no sooner perceived that his person was in danger than he ordered his charioteer to turn the heads of his horses for flight. This decided the fortunes of the day; it was the signal of his defeat, and his troops, on seeing it, at once broke from their ranks and fled from the field. The cavalry even, which on the extreme right had victory almost within their grasp, yielded to the general panic, and helped to swell the crowd of fugitives. As the narrowness of the plain allowed but very little room for escape, the vanquished were massacred in myriads. Darius escaped across the Euphrates, but his treasures and his family, consisting of his mother, wife, and children, fell into Alexander’s hands, who treated these illustrious captives with all the kindness and courtesy which were due alike to their misfortunes and their exalted rank.