He now set out from Susa, and, crossing the river Pasitigris,[442] invaded the country of the Uxians. Some of these people who inhabit the plains were under the rule of the viceroy of the Persians, and on this occasion surrendered to Alexander; but those who are called the mountaineers were not in subjection to the Persians, and at this time sent word to Alexander that they would not permit him to march with his forces into Persis, unless they received from him as much as they were in the habit of receiving from the king of the Persians for the passage through their mountains.[443] He sent the messengers back with instructions to come to the defiles, the possession of which made them think that the passage into Persis was in their power, promising them that they should there receive from him the prescribed toll. He then took the royal body-guards, the shield-bearing infantry, and 8,000 men from the rest of his army, and, under the guidance of the Susians, marched by night along a different road from the frequented one. Advancing by a route rough and difficult, on the same day he fell upon the villages of the Uxians, where he captured much booty and killed many of the people while still in their beds; but others escaped into the mountains. He then made a forced march to the defiles, where the Uxians resolved to meet him in mass in order to receive the prescribed toll. But he had already previously despatched Craterus to seize the heights, to which he thought the Uxians would retire if they were repelled by force; and he himself went, with great celerity, and got possession of the pass before their arrival. He then drew up his men in battle array, and led them from the higher and more commanding position against the barbarians. They, being alarmed at Alexander’s celerity, and finding themselves deprived by stratagem[444] of the position in which they had especially confided, took to flight without ever coming to close combat. Some of them were killed by Alexander’s men in their flight, and many lost their lives by falling over the precipices along the road; but most of them fled up into the mountains for refuge, and falling in with Craterus, were destroyed by his men. Having received these gifts of honour[445] from Alexander, they with difficulty, after much entreaty, procured from him the privilege of retaining possession of their own land on condition of paying him an annual tribute. Ptolemy, son of Lagus, says that the mother of Darius,[446] on their behalf, entreated Alexander to grant them the privilege of inhabiting the land. The tribute agreed upon was a hundred horses, five hundred oxen, and 30,000 sheep a year; for the Uxians had no money, nor was their country fit for tillage; but most of them were shepherds and herdsmen. CHAPTER XVIII. DEFEAT OF ARIOBARZANES AND CAPTURE OF PERSEPOLIS.