conquest of bactria, and pursuit of bessus across the oxus.

alexander now arrived at drapsaca, and having there given his army a rest, he marched to aornus and bactra, which are the largest cities in the land of the bactrians. these he took at the first assault; and left a garrison in the citadel of aornus, over which he placed archelaüs son of androcles, one of the companions. he appointed artabazus the persian, viceroy over the rest of the bactrians, who were easily reduced to submission. then he marched towards the river oxus, which flows from mount caucasus, and is the largest of all the rivers in asia which alexander and his army reached, except the indian rivers; but the indian rivers are the largest in the world. the oxus discharges its water into the great sea which is near hyrcania. when he attempted to cross the river it appeared altogether impassable; for its breadth was about six stades, and its depth was much greater than the proportion of its breadth. the bed of the river was sandy, and the stream so rapid, that stakes fixed deep into the bottom were easily rooted up from 200the earth by the mere force of the current, inasmuch as they could not be securely fixed in the sand. besides this, there was a scarcity of timber in the locality, and he thought it would take a long time and cause great delay, if they brought from a distance the materials needful for making a bridge over the river. therefore he collected the skins which the soldiers used for tent-coverings, and ordered them to be filled with chaff as dry as possible, and tied and stitched tightly together, so that the water might not penetrate into them.501 when these were filled and stitched together, they were sufficient to convey the army across in five days. but before he crossed the river, he selected the oldest of the macedonians, who were now unfit for military service, and such of the thessalians as had volunteered to remain in the army, and sent them back home. he then dispatched stasanor, one of the companions, into the land of the areians, with instructions to arrest arsames, the viceroy of that people, because he thought him disaffected, and to assume the office of viceroy of areia himself.

after passing over the river oxus, he made a forced march to the place where he heard that bessus was with his forces; but at this time messengers reached him from spitamenes and dataphernes, to announce that they would arrest bessus and hand him over to alexander if he would send to them a small army and a commander for it; since even at that very time they were holding him under guard, though they had not bound him with fetters. when alexander heard this, he gave his army rest, and marched more slowly than before. but he despatched ptolemy, son of lagus, at the head of three troops of the companion cavalry and all the horse-lancers, and of the infantry, the brigade of philotas, one regiment 201of 1,000 shield-bearing guards, all the agrianians, and half the archers, with orders to make a forced march to spitamenes and dataphernes. ptolemy went according to his instructions, and completing ten days’ march in four days, arrived at the camp where on the preceding day the barbarians under spitamenes had bivouacked.