Cyrus’s army now turned east across Syria and stopped at the city of Thapsacus. There Cyrus held a meeting of his generals and finally announced his real intentions: he was heading for Babylonia in the heart of the Persian Empire, where he would challenge the Great King. The soldiers complained of being kept in the dark, and demanded more money for such an undertaking. Cyrus promised each man five pounds of silver when they reached Babylon and full pay for their return journey. Again, the mercenaries were appeased by money.[25] Here the army crossed the chest-deep Euphrates river at a ford and entered Mesopotamia.[26]
The army hastened on in forced marches through desert country keeping the Euphrates River on their right, observing exotic animals they had never seen before—wild asses, gazelles, ostriches. Traversing desert country with scarce forage, many of their pack animals died of hunger, while the army ran short of grain and had to subsist on meat gained from hunting the exotic game. Cyrus knew that time was of the essence: he must attack before Artaxerxes could assemble his vast hosts from the ends of his empire—and especially before Abrocomas could reinforce him with his expeditionary army. Cyrus believed that “the faster he arrived, the more unprepared the king would be to fight.”[27] As Cyrus’s soldiers entered the land of Babylonia they knew the king and his army were not far away. Cyrus held a review of his troops and found that he had 13,000 Greek mercenaries and 100,000 non-Greek troops. He was reportedly facing a Persian army of 900,000, although a more reliable ancient estimate gives 400,000—still an enormous host.[28] Abrocomas’s legion from Syria took a long way around via the royal road and, as Cyrus had hoped, arrived too late to participate in the battle.[29]
Cyrus’ army came to a deep trench thirty feet wide and eighteen feet deep, extending for sixty miles, designed as a defensive barrier.[30] But the trench was abandoned. Cyrus’ army moved through a narrow passageway between the deep trench and the Euphrates. As they continued their march south they found numerous tracks of horses and men, signs of a great army retreating before them.[31]
[25].Xenophon Anabasis 1.4.6-13.
[26]. Xenophon Anabasis 1.4.18.
[27].Xenophon Anabasis 1.5.9.
[28]. Xenophon Anabasis 1.7.10-12. Xenophon gives 10,400 heavy infantry and 2,500 light infantry for the Greeks. But at 1.2.9 he had 13,000 already at Celaenae, before 1,100 Greeks joined Cyrus at Issus (1.4.3), which would suggest perhaps 14,000 troops in all. That Artaxerxes had 400,000 is the report of Ctesias from Plutarch Artaxerxes 13.3 and Diodorus 14.22.2.
[29].Xenophon Anabasis 1.7.12 with Briant 2002:628.
[30].Diodorus 14.22.3-4; on this account, Artaxerxes did not retreat from the trench, but he surely must have since the trench played no role in the battle. He was perhaps hoping to receive reinforcements from Abrocomas before he faced Cyrus.
[31].Xenophon Anabasis 1.5-7.