Menander, one of the Companions, was sent away into Lydia as viceroy; and Clearchus was put in command of the Grecian auxiliaries who had been under Menander. Asclepiodorus, son of Eunicus, was also appointed viceroy of Syria instead of Arimmas, because the latter seemed to have been remiss in collecting the supplies which he had been ordered to collect for the army which the king was about to lead into the interior. CHAPTER VII. PASSAGE OF THE EUPHRATES AND TIGRIS. Alexander arrived at Thapsacus in the month Hecatombaion,[381] in the archonship of Aristophanes at Athens; and he found that two bridges of boats had been constructed over the stream. But Mazaeus, to whom Darius had committed the duty of guarding the river, with about 3,000 cavalry, 2,000 of which were Grecian mercenaries, was up to that time keeping guard there at the river. For this reason the Macedonians had not constructed the complete bridge as far as the opposite bank, being afraid that Mazaeus might make an assault upon the bridge where it ended. But when he heard that Alexander was approaching, he went off in flight with all his army. As soon as he had fled, the bridges were completed as far as the further bank, and Alexander crossed upon them with his army.[382] Thence he marched up into the interior through the land called Mesopotamia, having the river Euphrates and the mountains of Armenia on his left. When he started from the Euphrates he did not march to Babylon by the direct road; because by going the other route he found all things easier for the march of his army, and it was also easier to obtain fodder for the horses and provisions for the men from the country. Besides this, the heat was not so scorching on the indirect route. Some of the men from Darius’s army, who were dispersed for the purpose of scouting, were taken prisoners; and they reported that Darius was encamped near the river Tigris, having resolved to prevent Alexander from crossing that stream. They also said that he had a much larger army than that with which he had fought in Cilicia. Hearing this, Alexander went with all speed towards the Tigris; but when he reached it he found neither Darius himself nor any guard which he had left. However he experienced great difficulty in crossing the stream, on account of the swiftness of the current,[383] though no one tried to stop him. There he made his army rest, and while so doing, an eclipse of the moon nearly total occurred.[384] Alexander thereupon offered sacrifice to the moon, the sun and the earth, whose deed this was, according to common report. Aristander thought that this eclipse of the moon was a portent favourable to Alexander and the Macedonians; that there would be a battle that very month, and that victory for Alexander was signified by the sacrificial victims. Having therefore decamped from the Tigris, he went through the land of Aturia,[385] having the mountains of the Gordyaeans[386] on the left and the Tigris