HE CROS^ES THE EUPHBATES AND TIGRIS. 151 "the Persian empire, and the natural place to find Darius.* But this march (as we know from Xenophon, who made it with the Ten Thousand Greeks) would be one of extreme suffering and tlirough a desert country where no provisions were to be got. Moreover, Mazaeus in retreating had taken a north-easterly di- rection towards the upper part of the Tigris ; and some prisoners reported that Darius with his main army was behind the Tigris, intending to defend the passage of that river against Alexander. The Tigris appears not to be fordable below Nineveh (Mo- sul). Accordingly he directed his march, first nearly northward, having the Euphrates on his left hand ; next eastward across Northern Mesopotamia, having the Armenian mountains on his left hand. On reaching the ford of the Tigris, he found it abso- lutely undefended. Not a single enemy being in sight, h^ forded the river as soon as possible, with all his infantry, cavalry., and baggage. The difiiculties and perils of crossing were extreme, from the depth of the water, above their breasts, the rapidity of the current, and the slippery footing.^ A resolute and vigilant enemy might have rendered the passage almost impossible. But the good fortune of Alexander was not less conspicuous in what his enemies left undone, than in what they actually did.^ After this fatiguing passage, Alexander rested for two days. During the night an eclipse of the moon occurred, nearly total ; which spread consternation among the army, combined with complaints against his overweening insolence, and mistrust as to the unknown regions on which they were entering. ' So Alexander considers Babylon ( Arrian, ii. 17, 3-10) — ■n-poxo>priaavTDv ^i)v ry 6vvufi£L tnl 'Qapv'kuva te Kal Aapelov tov te inl Ba/ivAcivof gto- Zov TTouiaduE&a, etc. This Is the explanation of Arrian's remarl<, iii. 7, 6 — where he assigns the reason why Alexander, after passing the Euphrates at Thapsakus, did not take the straight road towards Babylon. Cyrus the younger marched directly to Babylon to attack Artaxerxes. Susa, Ekbat- ana, and Persepolis were more distant, and less exposed to an enemy from the west.
- Arrian, iii. 7, 8; Diodor. xvii. 55 ; Curtius. iv. 9, 17-24. '• Magna mu-
nimenta regni Tigris atque Euphrates erant," is a part of the speech put into the mouth of Darius before the battle of Arbela, by Curtius, (iv. 14, 10). Both these great defences were abandoned. ^ Curtius, iv. 9, 23 ; Plutarch, Alexand. 39.