Anabasis by Xenophon
After these things the Hellenes and Ariaeus waited for Tissaphernes, being encamped close to one another: for more than twenty days they waited, during which time there came visitors to Ariaeus, his brother and other kinsfolk. To those under him came certain other Persians, encouraging them and bearing pledges to some of them from the king himself--that he would bear no grudge against them on account of the part they bore in the expedition against him with Cyrus, or for aught else of the things which were past. Whilst these overtures were being made, Ariaeus and his friends gave manifest signs of paying less attention to the Hellenes, so much so that, if for no other reason, the majority of the latter were not well pleased, and they came to Clearchus and the other generals, asking what they were waiting for. "Do we not know full well," they said, "that the king would give a great deal to destroy us, so that other Hellenes may take warning and think twice before they march against the king. To-day it suits his purpose to induce us to stop here, because his army is scattered; but as soon as he has got together another armament, attack us most certainly he will. How do we know he is not at this moment digging away at trenches, or running up walls, to make our path impassable. It is not to be supposed that he will desire us to return to Hellas with a tale how a handful of men like ourselves beat the king at his own gates, laughed him to scorn, and then came home again." Clearchus replied: "I too am keenly aware of all this; but I reason thus: if we turn our backs now, they will say, we mean war and are acting contrary to the truce, and then what follows? First of all, no one will furnish us with a market or means of providing ourselves with food. Next, we shall have no one to guide us; moreover, such action on our part will be a signal to Ariaeus to hold aloof from us, so that not a friend will be left to us; even those who were formerly our friends will now be numbered with our enemies. What other river, or rivers, we may find we have to cross, I do not know; but this we know, to cross the Euphrates in face of resistance is impossible. You see, in the event of being driven to an engagement, we have no cavalry to help us, but with the enemy it is the reverse--not only the most, but the best of his troops are cavalry, so that if we are victorious, we shall kill no one, but if we are defeated, not a man of us can escape. For my part, I cannot see why the king, who has so many advantages on his side, if he desires to destroy us, should swear oaths and tender solemn pledges merely in order to perjure himself in the sight of heaven, to render his word worthless and his credit discreditable the wide world over." These arguments he propounded at length.
Meanwhile Tissaphernes came back, apparently ready to return home; he had his own force with him, and so had Orontas, who was also present, his. The latter brought, moreover, his bride with him, the king's daughter, whom he had just wedded. The journey was now at length fairly commenced. Tissaphernes led the way, and provided a market. They advanced, and Ariaeus advanced too, at the head of Cyrus's Asiatic troops, side by side with Tissaphernes and Orontas, and with these two he also pitched his camp. The Hellenes, holding them in suspicion, marched separately with the guides, and they encamped on each occasion a parasang apart, or rather less; and both parties kept watch upon each other as if they were enemies, which hardly tended to lull suspicion; and sometimes, whilst foraging for wood and grass and so forth on the same ground, blows were exchanged, which occasioned further embitterments. Three stages they had accomplished ere they reached the wall of Media, as it is called, and passed within it. It was built of baked bricks laid upon bitumen. It was twenty feet broad and a hundred feet high, and the length of it was said to be twenty parasangs. It lies at no great distance from Babylon.
From this point they marched two stages--eight parasangs--and crossed two canals, the first by a regular bridge, the other spanned by a bridge of seven boats. These canals issued from the Tigris, and from them a whole system of minor trenches was cut, leading over the country, large ones to begin with, and then smaller and smaller, till at last they become the merest runnels, like those in Hellas used for watering millet fields. They reached the river Tigris. At this point there was a large and thickly populated city named Sittace, at a distance of fifteen furlongs from the river. The Hellenes accordingly encamped by the side of that city, near a large and beautiful park, which was thick with all sorts of trees.
The Asiatics had crossed the Tigris, but somehow were entirely hidden from view. After supper, Proxenus and Xenophon were walking in front of the place d'armes, when a man came up and demanded of the advanced guard where he could find Proxenus or Clearchus. He did not ask for Menon, and that too though he came from Ariaeus, who was Menon's friend. As soon as Proxenus had said: "I am he, whom you seek," the man replied: "I have been sent by Ariaeus and Artaozus, who have been trusty friends to Cyrus in past days, and are your well-wishers. They warn you to be on your guard, in case the barbarians attack you in the night. There is a large body of troops in the neighbouring park. They also warn you to send and occupy the bridge over the Tigris, since Tissaphernes is minded to break it down in the night, if he can, so that you may not cross, but be caught between the river and the canal." On hearing this they took the man to Clearchus and acquainted him with his statement. Clearchus, on his side, was much disturbed, and indeed alarmed at the news. But a young fellow who was present, struck with an idea, suggested that the two statements were inconsistent; as to the contemplated attack and the proposed destruction of the bridge. Clearly, the attacking party must either conquer or be worsted: if they conquer, what need of their breaking down the bridge? "Why! if there were half a dozen bridges," said he, "we should not be any the more able to save ourselves by flight--there would be no place to flee to; but, in the opposite case, suppose we win, with the bridge broken down, it is they who will not be able to save themselves by flight; and, what is worse for them, not a single soul will be able to bring them succour from the other side, for all their numbers, since the bridge will be broken down."
 Possibly Xenophon himself.
Clearchus listened to the reasoning, and then he asked the messenger, "How large the country between the Tigris and the canal might be?" "A large district," he replied, "and in it are villages and cities numerous and large." Then it dawned upon them: the barbarians had sent the man with subtlety, in fear lest the Hellenes should cut the bridge and occupy the island territory, with the strong defences of the Tigris on the one side and of the canal on the other; supplying themselves with provisions from the country so included, large and rich as it was, with no lack of hands to till it; in addition to which, a harbour of refuge and asylum would be found for any one, who was minded to do the king a mischief.
After this they retired to rest in peace, not, however, neglecting to send a guard to occupy the bridge in spite of all, and there was no attack from any quarter whatsoever; nor did any of the enemy's people approach the bridges: so the guards were able to report next morning. But as soon as it was morning, they proceeded to cross the bridge, which consisted of thirty-seven vessels, and in so doing they used the utmost precaution possible; for reports were brought by some of the Hellenes with Tissaphernes that an attempt was to be made to attack them while crossing. All this turned out to be false, though it is true that while crossing they did catch sight of Glus watching, with some others, to see if they crossed the river; but as soon as he had satisfied himself on that point, he rode off and was gone.
From the river Tigris they advanced four stages--twenty parasangs--to the river Physcus, which is a hundred feet broad and spanned by a bridge. Here lay a large and populous city named Opis, close to which the Hellenes were encountered by the natural brother of Cyrus and Artaxerxes, who was leading a large army from Susa and Ecbatana to assist the king. He halted his troops and watched the Helleens march past. Clearchus led them in column two abreast: and from time to time the vanguard came to a standstill, just so often and just so long the effect repeated itself down to the hindmost man: halt! halt! halt! along the whole line: so that even to the Hellenes themselves their army seemed enormous; and the Persian was fairly astonished at the spectacle.
From this place they marched through Media six desert stages--thirty parasangs--to the villages of Parysatis, Cyrus's and the king's mother. These Tissaphernes, in mockery of Cyrus, delivered over to the Hellenes to plunder, except that the folk in them were not to be made slaves. They contained much corn, cattle, and other property. From this place they advanced four desert stages--twenty parasangs--keeping the Tigris on the left. On the first of these stages, on the other side of the river, lay a large city; it was a well-to-do place named Caenae, from which the natives used to carry across loaves and cheeses and wine on rafts made of skins.