Soon after his accession, Alexander had been voted the leadership of the Persian expedition by the League of Corinth. He set out for Asia in the spring (334). Ancient writers sometimes speak in an implausible way of wars being planned by a father and executed by a son (such as the Macedonian king Perseus’s war against Rome, allegedly planned by his father, Philip V). Alexander’s invasion of Asia, however, is surely a clear case where a son does seem automatically to have taken over a great project, one which had been in the cards since the Battle of Cunaxa at the beginning of the century. Philip had created the army, the prosperity, and the human resources that enabled Alexander to embark on his Asian campaign. He left behind his general Antipater as governor of Greece, with 12,000 foot soldiers and 1,500 cavalry, while taking 40,000 foot soldiers (12,000 of them Macedonians) and more than 6,000 cavalry with him to Asia. To what extent Alexander needed to reorganize the army at the outset of the expedition is unclear. It is certain that he made changes during it; for instance, he incorporated Iranian troops to deal with special circumstances in his eastern campaigning and changed the structure of the cavalry so as to reduce the politically dangerous territorial affiliations of the individual brigades (ilai, squadrons of Macedonian cavalry, were replaced by hipparchies). From the first, however, he must have given thought to problems of reconnaissance and supply. Whereas Greek armies expected to live off the land to some extent, Alexander used wagons, despite a tradition that Philip had forced his soldiers to carry their own provisions and equipment. The core of the infantry was the Macedonian phalanx, armed with the long sarissa, or spear; the pick of the cavalry were the Companions, led by Alexander himself on the right wing. Philip’s great general Parmenio commanded the Thessalian cavalry on the left. In addition, there were lighter armed troops, such as the scouts, and less-coordinated but highly effective contingents of slingers and other irregulars, usually from the parts of Greece where the concept of polis was imperfectly developed. This army was a formidable machine in the metaphorical sense. There also were literal machines—stone-throwing siege engines that could be assembled on the spot. The Thessalian siege engineers associated with Philip certainly continued into Alexander’s reign and enabled him to conquer Anatolia and Phoenicia at comparatively high speed, given the fortified obstacles confronting him.
The Spartan Agesilaus may have hoped merely to construct a belt of rebel satraps, and Philip’s ultimate aims are inscrutable. Alexander, however, as soon as he had crossed the Hellespont, cast his spear into Asian soil and openly declared that he laid claim to all Asia (admittedly a geographically fluid concept). At Troy he visited the tombs of the heroes Achilles and Ajax, paying them due religious honour; this was an early and emphatic statement that he saw himself and his expedition in epic, Homeric terms. The conquest of Asia (in the sense of the Persian empire) was more feasible than it had been in 346: Artaxerxes III had died in 338–337, and the king now reigning was the much weaker Darius III (he succeeded in 336, after the brief reign of Arses, whom the trilingual inscription found at Xanthus in 1973 shows to have borne the title Artaxerxes IV).
It was in this region, at the Granicus River, that Alexander was confronted by a Persian army—not the central army of the Persian king but a very sizable force levied by the satraps from Anatolia itself. Alexander attacked in full daylight (the vulgate tradition of a “dawn attack” should probably be rejected); the Persians lined the opposite riverbank—impressively but suicidally. Alexander’s victory was achieved in part by his own conspicuous example; he led the right wing with a battle cry to the god of battles. Such “heroic leadership” is, indeed, one of Alexander’s main contributions to the history of generalship.
Alexander immediately appointed satraps in the parts of Anatolia thus acquired, thereby giving an early signal that he saw himself as in some sense the successor and continuator of the Achaemenid Persian kings, not merely as an outsider devoted to their overthrow. At the same time, he proclaimed democracy, restored law, and remitted tribute in the Ionian cities. This illustrates how seriously Alexander took the propaganda purpose of the war as revenge for the Persian impieties of 480: it is noticeable that the places he accorded specially favourable treatment in his passage through Anatolia often turn out to be places with a “good” record in the Ionian revolt or the Persian Wars; that is to say, they had been prominent rebels. Alexander felt no scruple about subjecting to direct satrapal rule the tracts of territory outside the poleis. Whether the Greek cities of Anatolia joined the League of Corinth is an intractable question. Some of the islanders certainly did, as, for instance, Chios, where an inscription recording the terms of Alexander’s settlement proclaims bluntly that “the constitution is to be a democracy” and refers to the “decrees of the Greeks.” As for Asiatic cities like Priene, there is no certainty, but the probability is that they joined the league.
Priene was a very old city indeed, one of the Ionian “Dodecapolis,” but it was physically derelict. It is possible that Alexander in some sense refounded this and other western Anatolian Greek cities, such as Heraclea south of Latmus and Smyrna. (There is, however, an almost equally strong case for associating their physical reconstruction with the Carian Hecatomnids, the family of Mausolus). If Alexander was their founder, this would be the first good evidence of the urbanizing that was a marked feature of his policy for the conquered territories to the south and east. In this respect, however, as in others, credit should be given to Philip for his example: Philippi (the renamed Crenides) was not his only city foundation.
At Halicarnassus, Alexander met his most-serious resistance so far from a defended city, in mid-334; Miletus had not delayed him long (nor was it punished very severely—it had after all been the leader of the Ionian revolt). The siege of Halicarnassus was a far tougher operation. The city had good defenses, both natural and artificial, and had been chosen as the local Persian military headquarters. The fighting was severe, though in the apologetic tradition used by Arrian the severity is minimized. At one moment Alexander was forced to the extremity of having to send a herald to ask for the bodies of some Macedonians who had fallen in front of the walls. After the city was taken—the citadels held out for another year or two—Alexander reappointed the native princess Ada as satrap (his earlier satrapal appointees had been Macedonians). She was the sister of the great Mausolus, and her reinstatement prefigures Alexander’s shrewd subsequent policy of allowing local men and women to remain in post (though usually, like Ada herself, under the superintendence of a Macedonian troop commander). A romantic story makes her “adopt” Alexander as her son, a gesture graciously accepted by Alexander. That gesture of conciliation toward the native population was good politics.
After the conquest of Halicarnassus, Alexander moved east, meanwhile sending to Macedon for drafts of reinforcements. The scale of these demands through the whole campaign and their effects on the domestic situation in Macedon are not easy to estimate; the record of the literary sources is too fitful and episodic. According to one view, Alexander’s legacy was one of lasting damage; he had exhausted the manpower of Macedon to such a point that the Macedon of Philip V and Perseus inevitably succumbed to the Romans with their almost infinite capacity for replacement. On the other hand, one must allow in the reckoning for a good deal of voluntary emigration by Macedonians to the armies and cities of the successor kingdoms in the Hellenistic period. Thus, Alexander was not the only culprit; there were more-intangible demographic forces at work.