No sooner had the chariot attack failed, and the space between the two lines of battle become clear, than Alexander, with the quick eye of a true general, saw his opportunity: to resist his flank movement, the Bactrians and Sacae with the greater part of the left wing had broken off from the main Persian line, and in pressing towards the left had made a gap between their ranks and the centre. Into this gap the Macedonian king, at the head of the “Companion” cavalry and a portion of the phalanx, plunged. Here he found himself in the near neighborhood of Darius, whereupon he redoubled the vigor of his assault, knowing the great importance of any success gained in this quarter. The Companions rushed on with loud cries, pressing with all their weight, and thrusting their spears into the faces of their antagonists--the phalanx, bristling with its thick array of lances, bore them down. Alexander found himself sufficiently near Darius to hurl a spear at him, which transfixed his charioteer. The cry arose that the king had fallen, and the ranks at once grew unsteady. The more timid instantly began to break and fly; the contagion of fear spread; and Darius was in a little while almost denuded of protection on one side. Seeing this, and regarding the battle as lost, since his line was broken, his centre and left wing defeated, while only his right wing remained firm, the Persian monarch yielded to his alarm, and hastily quitting the field, made his way to Arbela. The centre and left fled with him. The right, which was under the command of the Syrian satrap, Mazseus, made a firmer stand. On this side the chariots had done some damage, and the horse was more than a match for the Thessalian cavalry. Parmenio found himself in difficulties about the time when the Persian king fled. His messengers detained a part of the phalanx, which was about to engage in the pursuit, and even recalled Alexander, who was hastening upon the track of Darius. The careful prince turned back, but before he could make his way through the crowd of fugitives to the side of his lieutenant, victory had declared in favor of the Macedonians in this part of the field also. Mazseus and his troops, learning that the king was fled, regarded further resistance as useless, and quitted the field. The Persian army hurriedly recrossed the Zab, pursued by the remorseless conquerors, who slew the unresisting fugitives till they were weary of slaughter. Arrian says that 300,000 fell, while a still larger number were taken prisoners. Other writers make the loss considerably less. All, however, agree that the army was completely routed and dispersed, that it made no attempt to rally, and gave no further trouble to the conqueror.