Miscellaneous Grecian—under Erigyius
600
Thracian and Pæonian (light)—under Cassander
900
Total cavalry
4,500
Such seems the most trustworthy enumeration of Alexander’s first invading army. There were, however, other accounts, the highest of which stated as much as forty-three thousand infantry with four thousand cavalry. Besides these troops, also, there must have been an effective train of projectile machines and engines, for battles and sieges, which we shall soon find in operation. As to money, the military chest of Alexander, exhausted in part by profuse donatives to his Macedonian officers, was as poorly furnished as that of Napoleon Bonaparte on first entering Italy for his brilliant campaign of 1796. According to Aristobulus, he had with him only seventy talents [£14,000 or $70,000]; according to another authority, no more than the means of maintaining his army for thirty days.
Previously the Macedonian generals Parmenion and Calas had crossed into Asia with bodies of troops. Parmenion, acting in Æolis, took Grynia, but was compelled by Memnon to raise the siege of Pitane; while Calas, in the Troad, was attacked, defeated, and compelled to retire to Rhœteum.
We thus see that during the season preceding the landing of Alexander, the Persians were in considerable force, and Memnon both active and successful even against the Macedonian generals, on the region northeast of the Ægean. This may help to explain that fatal imprudence, whereby the Persians permitted Alexander to carry over without opposition his grand army into Asia, in the spring of 334 B.C. They possessed ample means of guarding the Hellespont, had they chosen to bring up their fleet, which, comprising as it did the force of the Phœnician towns, was decidedly superior to any naval armament at the disposal of Alexander. The Persian fleet actually came into the Ægean a few weeks afterwards. Now Alexander’s designs, preparations, and even intended time of march, must have been well known not merely to Memnon, but to the Persian satraps in Asia Minor, who had got together troops to oppose him. These satraps unfortunately supposed themselves to be a match for him in the field, disregarding the pronounced opinion of Memnon to the contrary, and even overruling his prudent advice by mistrustful and calumnious imputations.
At the time of Alexander’s landing, a powerful Persian force was already assembled near Zelia in the Hellespontine Phrygia, under command of Arsites the Phrygian satrap, supported by several other leading Persians, Spithridates (satrap of Lydia and Ionia), Pharnaces, Atizyes, Mithridates, Rheomithres, Niphates, Petines, etc. Forty of these men were of high rank (denominated kinsmen of Darius), and distinguished for personal valour. The greater number of the army consisted of cavalry, including Medes, Bactrians, Hyrcanians, Cappadocians, Paphlagonians, etc. In cavalry they greatly outnumbered Alexander; but their infantry was much inferior in number, composed, however, in large proportion, of Grecian mercenaries. The Persian total is given by Arrian as twenty thousand cavalry, and nearly twenty thousand mercenary foot; by Diodorus as ten thousand cavalry, and one hundred thousand infantry; by Justin even at six hundred thousand. The numbers of Arrian are the more credible; in those of Diodorus the total of infantry is certainly much above the truth—that of cavalry probably below it.
Memnon, who was present with his sons and with his own division, earnestly dissuaded the Persian leaders from hazarding a battle. Reminding them that the Macedonians were not only much superior in infantry, but also encouraged by the leadership of Alexander, he enforced the necessity of employing their numerous cavalry to destroy the forage and provisions,—and if necessary, even towns themselves,—in order to render any considerable advance of the invading force impracticable. While keeping strictly on the defensive in Asia, he recommended that aggressive war should be carried into Macedonia; that the fleet should be brought up, a powerful land-force put aboard, and strenuous efforts made, not only to attack the vulnerable points of Alexander at home, but also to encourage active hostility against him from the Greeks and other neighbours.