But as soon as Darius was certified of Alexander’s approach for battle, he conveyed about 30,000 of his cavalry and with them 20,000 of his light-armed infantry across the river Pinarus, in order that he might be able to draw up the rest of his forces with ease. Of the heavy armed infantry, he placed first the 30,000 Greek mercenaries to oppose the phalanx of the Macedonians, and on both sides of these he placed 60,000 of the men called Cardaces,[244] who were also heavy-armed infantry.[245] For the place where they were posted was able to contain only this number in a single phalanx.[246] He also posted 20,000 men near the mountain on their left and facing Alexander’s right. Some of these troops were also in the rear of Alexander’s army; for the mountain near which they were posted in one part sloped a great way back and formed a sort of bay, like a bay in the sea, and afterwards bending forwards caused the men who had been posted at the foot of it to be behind Alexander’s right wing. The remaining multitude of Darius’s light-armed and heavy-armed infantry was marshalled by nations to an unserviceable depth and placed behind the Grecian mercenaries and the Persian army arranged in phalanx. The whole of the army with Darius was said to number about 600,000 fighting men.[247] As Alexander advanced, he found that the ground spread out a little in breadth, and he accordingly brought up his horsemen, both those called Companions, and the Thessalians as well as the Macedonians, and posted them with himself on the right wing. The Peloponnesians and the rest of the allied force of Greeks he sent to Parmenio on the left. When Darius had marshalled his phalanx, by a pre-concerted signal he recalled the cavalry which he had posted in front of the river for the express purpose of rendering the arranging of his army easy. Most of these he placed on the right wing near the sea facing Parmenio; because here the ground was more suitable for the evolutions of cavalry. A certain part of them also he led up to the mountain towards the left. But when they were seen to be useless there on account of the narrowness of the ground, he ordered most of these also to ride round to the right wing and join their comrades there. Darius himself occupied the centre of the whole army, inasmuch as it was the custom for the kings of Persia to take up that position, the reason of which arrangement has been recorded by Xenophon, son of Gryllus.[248] CHAPTER IX. ALEXANDER CHANGES THE DISPOSITION OF HIS FORCES.