When Alexander had finished his operations among the Sogdianians, and was now in possession of the rock, he advanced into the land of the Paraetacians, because many of the barbarians were said to be holding another rock, a strongly fortified place in that country. This was called the rock of Chorienes; and to it Chorienes himself and many other chiefs had fled for refuge. The height of this rock was about twenty stades, and the circuit about sixty. It was precipitous on all sides, and there was only one ascent to it, which was narrow and not easy to mount, since it had been constructed in spite of the nature of the place. It was therefore difficult to ascend even by men in single file and when no one barred the way. A deep ravine also enclosed[591] the rock all round, so that whoever intended to lead an army up to it, must long before make a causeway of earth over this ravine in order that he might start from level ground, when he led his troops to the assault. Notwithstanding all this, Alexander undertook the enterprise. To so great a pitch of audacity had he advanced through his career of success, that he thought every place ought to be accessible to him,[592] and to be captured by him. He cut down the pines, which were very abundant and lofty all round the mountain, and made ladders of them, so that by means of them the soldiers might be able to descend into the ravine[593]; for otherwise it was impossible for them to do so. During the daytime he himself superintended the work, keeping half of his army engaged in it; and during the night his confidential body-guards, Perdiccas, Leonnatus, and Ptolemy, son of Lagus, in turn with the other half of the army, divided into three parts, performed the duty which had been assigned to each for the night. But they could complete no more than twenty cubits in a day, and not quite so much in a night, though the whole army engaged in the labour; so difficult was the place to approach and so hard was the work in it. Descending into the ravine, they fastened pegs into the sharpest and narrowest part of it, distant from each other as far as was consistent with strength to support the weight of what was placed upon them. Upon these they placed hurdles made of willow and osiers, very much in the form of a bridge. Binding these together, they loaded earth above them, so that there might be an approach to the rock for the army on level ground. At first the barbarians derided, as if the attempt was altogether abortive; but when the arrows began to reach the rock, and they were unable to drive back the Macedonians, though they themselves were on a higher level, because the former had constructed screens to ward off the missiles, that they might carry on their labour under them without receiving injury, Chorienes grew alarmed at what was being done, and sent a herald to Alexander, beseeching him to send Oxyartes up to him. Alexander accordingly sent Oxyartes, who on his arrival persuaded