The battle thus offered was eagerly accepted by the Macedonian.  If he could not defeat with ease a Persian force not greatly exceeding his own, he had miscalculated the relative goodness of the soldiers on either side, and might as well desist from the expedition.  Accordingly, he no sooner came to the bank of the river, and saw the enemy drawn up on the other side, than, rejecting the advice of Parmenio to wait till the next day, he gave orders that the whole army should enter the stream and advance across it.  The Granicus was in most places fordable; but there were occasional deeper parts, which had to be avoided; and there was thus some difficulty in reaching the opposite bank in line.  That bank itself was generally steep and precipitous, but offered also several gentle slopes where a landing was comparatively easy.  The Persians had drawn up their cavalry along the line of the river close to the water’s edge, and had placed their infantry in the rear.  Alexander consequently attacked with his cavalry.  The engagement began upon the right.  Amytas and Ptolemy, who were the first to reach the opposite bank, met with a strenuous resistance and were driven back into the stream by the forces of Memnon and his sons.  The battle, however, on this side was restored by Alexander himself, who gradually forced the Persians back after a long hand-to-hand fight, in which he received a slight wound, and slew with his own hand several noble Persians.  Elsewhere the resistance was less determined.  Parmenio crossed on the left with comparative ease, by his advance relieving Alexander.  The Persians found the long spears of the Macedonians and their intermixture of light-armed foot with heavy-armed cavalry irresistible.  The Macedonians seem to have received orders to strike at their adversaries’ faces—­a style of warfare which was as unpleasant to the Persians as it was to the soldiers of Pompey at Pharsalia.  Their line was broken where it was opposed to Alexander and his immediate companions; but the contagion of disorder rapidly spread, and the whole body of the cavalry shortly quitted the field, after having lost a thousand of their number.  Only the infantry now remained.  Against these the Macedonian phalanx was brought up in front, while the cavalry made repeated charges on either flank with overwhelming effect.  Deserted by their horse, vastly outnumbered, and attacked on all sides, the brave mercenaries stood firm, fought with desperation, and were mostly slaughtered where they stood.  Two thousand out of the 20,000—­probably wounded men—­were made prisoners.  The rest perished, except a few who lay concealed among the heaps of slain.