In this array, both parties remained for some time, watching each other in anxious silence. There being no firing or smoke, as with modern armies, all the details on each side were clearly visible to the other; so that the Persians easily recognised Alexander himself on the Macedonian right from the splendour of his armour and military costume, as well as from the respectful demeanour of those around him. Their principal leaders accordingly thronged to their own left, which they reinforced with the main strength of their cavalry, in order to oppose him personally. Presently he addressed a few words of encouragement to the troops, and gave the order for advance. He directed the first attack to be made by the squadron of companion-cavalry whose turn it was on that day to take the lead (the squadrons of Apollonia, of which Socrates was captain, commanded on this day by Ptolemæus son of Philippus), supported by the light horse or Lancers, the Pæonian darters (infantry), and one division of regularly armed infantry, seemingly hypaspists. He then himself entered the river, at the head of the right half of the army, cavalry and infantry, which advanced under sound of trumpets and with the usual war-shouts. As the occasional depths of water prevented a straightforward march with one uniform line, the Macedonians slanted their course suitably to the fordable spaces; keeping their front extended so as to approach the opposite bank as much as possible in line, and not in separate columns with flanks exposed to the Persian cavalry. Not merely the right under Alexander, but also the left under Parmenion, advanced and crossed in the same movement and under the like precautions.
The foremost detachment under Ptolemy and Amyntas, on reaching the opposite bank, encountered a strenuous resistance, concentrated as it was here upon one point. They found Memnon and his sons with the best of the Persian cavalry immediately in their front; some on the summit of the bank, from whence they hurled down their javelins—others down at the water’s edge, so as to come to closer quarters. The Macedonians tried every effort to make good their landing, and push their way by main force through the Persian horse, but in vain. Having both lower ground and insecure footing, they could make no impression, but were thrust back with some loss, and retired upon the main body which Alexander was now bringing across. On his approaching the shore, the same struggle was renewed around his person with increased fervour on both sides. He was himself among the foremost, and all near him were animated by his example. The horsemen on both sides became jammed together, and the contest was one of physical force and pressure by man and horse; but the Macedonians had a great advantage in being accustomed to the use of the strong close-fighting pike, while the Persian weapon was the missile javelin. At length the resistance was surmounted, and Alexander, with those around him, gradually thrusting back the defenders, made good their way up the high bank to the level ground. At other points the resistance was not equally vigorous. The left and centre of the Macedonians, crossing at the same time on all practicable spaces along the whole line, overpowered the Persians stationed on the slope, and got up to the level ground with comparative facility. Indeed no cavalry could possibly stand on the bank to offer opposition to the phalanx with its array of long pikes, wherever this could reach the ascent in any continuous front. The easy crossing of the Macedonians at other points helped to constrain those Persians, who were contending with Alexander himself on the slope, to recede to the level ground above.