This old king, then, suggested to Kobad that instead of campaigning as usual among the head-waters of Euphrates and Tigris, where the Romans had a number of walled cities to fall back upon if attacked, he should take a southerly route, which no Persian Army had ever taken before, following the Euphrates. At the point where the river-course turns from west to north he should strike across the Syrian desert. For here, beyond the desert, the Romans, trusting to the natural defences of waterless sand and rock, had built only few fortifications, and these were manned by no troops worth the name. If vigorously attacked, Antioch would fall into their hands without a struggle, because — he was justified in this comment — Antioch is the most unserious city in the entire East, the inhabitants having only four interests, namely wine, sex, Hippodrome politics, and religious argument. (Trade is not an interest, but a disagreeable necessity to which they submit in order to keep themselves in funds for the active prosecution of these four exciting interests.) What a magnificent city to plunder! And the raiders could return safely with their spoils long before any rescue could arrive from Roman Mesopotamia.
Kobad was interested but sceptical. If no Persian Army in the past had found this approach feasible, in what way had conditions altered to make it so? How would an army, unaccustomed to temporary starvation and thirst, maintain itself in the parched, pastureless desert?
The King of the Saracens replied to the first question that hitherto the Great King had never called upon an experienced Saracen for advice. As for the second question: the Persian force should consist entirely of light cavalry — infantry and heavy cavalry were ruled out — and they should make their expedition in the spring, when there would be ample pasture, even in the wildest desert, for those who knew where to look for it; and they should travel light; and the Saracens would be waiting for them, at a point on the river well within the Roman territories, with sufficient food and water for the last and most difficult stage of the journey.
Kobad was persuaded by the King of the Saracens, though Saracens are a notoriously faithless race; because he could surely have no motive in making these suggestions but to obtain Persian help in a profitable raid which was on too large a scale for himself to undertake alone. All that Kobad needed to guard against was treachery during the return journey, and he would therefore insist on the King of the Saracens leaving his two sons and two grandsons as hostages at the Persian Court at Susa until the campaign was over. The Saracen agreed to do so, and by March of the next year — the year following the battle of Daras — all preparations had been made. The expedition assembled at Ctesiphon in Assyria, 15,000 strong, under the command of an able Persian named Azareth.
They passed the Euphrates just above the city of Babylon and continued along the southern bank through uninhabited country until they reached the Roman frontier station at Circesium, where there were only a few Customs police. From there they pushed on rapidly astride the Roman road, which, after following the river for a hundred miles, curves south to Palmyra and Damascus. They were now joined by a large body of Saracens under their King; who told Azareth that the route lay straight across the desert to Chalcis, a walled town, which was almost the only obstacle to be encountered between them and Antioch, and this was no obstacle cither, because it had a garrison of only 200 men. Azareth did not altogether trust the Saracens, though they had brought the stipulated amount of provisions. He therefore waited until scouts, sent ahead under Saracen escort, should report back that the desert pasture was plentiful, and that no ambush had been laid for them on the other side.
But to allow himself this delay was to underrate the energy of Belisarius, who had recently introduced a system of linked look-outs, with agreed smoke-signals, as a protection against fronticr-raids. Within an hour of the Persians' arrival at Circesium, 200 miles across the Southern desert, Belisarius at Daras had learned the numbers and composition of their forces and had taken his decision. Leaving only slight garrisons behind in Daras and the other frontier cities, he hurried by forced marches to the relief of Antioch at the head of all the trained troops that he could assemble which, at such short notice, amounted to only 8,000 men; but he picked up reinforcements on the line of march to the number of 8,000 more. He took the southern road, by way of Carrhae (famous for the crushing defeat by the Persians of Crassus, colleague to Julius Caesar) and managed with his main cavalry forces to reach Clialcis, 300 miles way, in seven days, just in time to man the fortifications. But it was a close race, for by now Azareth was across the desert and only half a day's march away from Chalcis — among the very rocks where St Jerome and his mad fellow-ascetics once lived like angry scorpions, worshipping God indeed, but ungratefully rejecting God's creation of all pleasant and beautiful things. On the same morning Belisarius was joined by 5,000 Arab horsemen from the Northern Syrian desert, where they had been pasturing their horses. They were the subjects of King Harith ibn Gabala of Bostra in Transjordania, to whom Justinian paid a yearly sum in gold on condition that he checked Saracen raids on Syria. These Arabs were not reliable soldiers, however, and King Harith was suspected of having an understanding with the Saracens, because whenever there had been a Saracen raid his men had always arrived two or three days too late; but Belisarius was glad to have them with him, because in the absence of his infantry, who were still on the way, they increased his numbers to 21,000 men.
Azareth was disgusted with himself when his vanguard, pressing on to Chalcis, was suddenly thrown back on the main body by a Roman cavalry charge. He had let his opportunity slip, and could not now reach Antioch without risking a battle against the same general and the same troops that had fought so well at Daras. If he were defeated at such a distance from the frontier, and on the wrong side of the Syrian desert, it was unlikely that a single Persian would survive the return journey — the Saracens would save their own skins, melting into the desert which they knew so well. Even if he were victorious, he would not be able, probably, to prevent Belisarius taking refuge with the surviving remnant of his forces behind the walls of Chalcis. It would be dangerous to continue the raid on Antioch, with Chalcis lying uncaptured in his rear and Roman reinforcements on the way. So he took the wise decision to retrace his steps, with no gains and no losses, while he still had provisions and while the weather remained temperate. He consoled himself with the reflection that even if he had reached Chalcis before Belisarius, and pushed on to Antioch, and plundered it, then his forces — especially the Saracens — would have been disorganized by victory, and Belisarius would have intercepted him on his return and again had the advantage of choosing the battleground and standing on the defensive, as at Daras. The King of the Saracens agreed that retirement was now the only course; he did not dare to break his own forces up into small raiding parties and go off plundering to the southward, for fear that Azareth would report to Kobad that he had been deserted, and that Kobad would put his Saracen hostages to death. So the Persians and Saracens faced about and marched homeward, and Belisarius followed close behind them to make sure that they did not turn and come back again into Syria by some other route. Neither army hurried or attempted any hostilities against the other. Belisarius remained at a day's distance behind Azareth and encamped each night at the place which Azareth had abandoned that morning. He kept a sharp look-out on his own flanks and rear, in case of sudden surprise by the Saracens.