The point at which he reached the Jaxartes is probably the site of the modern Khojend: there he determined to build a town, but the execution of his design was retarded by a rebellion of the Soghdians and the Bactrians. The natives also overpowered the garrisons which he had established in seven different towns on the banks of the Jaxartes, the most important of which was Cyropolis. Alexander crushed the rebels and re-established his authority on the Jaxartes in the course of a few days. At this juncture he received news of two serious events. The Sacæ, or Scythians, had collected an army on the opposite bank of the river; while Spitamenes, in whom, owing to his past conduct, he had placed reliance, was besieging the Macedonian garrison left at Marcanda. Alexander despatched a considerable force against Spitamenes, while he himself turned towards the Jaxartes, on the left bank of which he built a city in the space of seventeen days, calling it Alexandria according to his custom. It was surrounded by a wall 60 stadia[10] in circumference. Hemmed in as he now was by enemies on all sides, and weakened by sickness, he stood in great need of that magnificent self-confidence which is the birthright of conquerors. Moreover, his army was becoming disheartened, and was disinclined to attempt the passage of the river in the teeth of an enemy drawn up in battle array on the opposite bank. But he was daunted by no difficulty or danger. After completing his new capital he ordered the construction of a multitude of rafts, on which he carried his whole army in safety, fell on the Scythians, and put them to utter rout. They recognised the uselessness of further resistance, and sent envoys to announce their submission. Meanwhile the division which had been sent to relieve the garrison of Marcanda had been annihilated by Spitamenes in the valley of the Polytimetus, or Zarafshan. On hearing of this disaster Alexander set out in haste for Marcanda, which he reached in four days. Spitamenes on the first news of his approach fled into Bactria. Alexander started in pursuit, but, despairing of overtaking him, turned back and laid waste the whole valley. He took up his winter quarters in Zariaspa.[11] During this winter (B.C. 329–328) he received reinforcements from Greece of 19,000 men, which enabled him to overrun Margiana in the following spring. There remained now but one stronghold unsubdued, namely, Petra Oxiana,[12] which was provisioned for two years, and defended by a Soghdian named Arimazes.[13] It finally capitulated, and its brave defender, together with his relatives and the principal nobility, were crucified by the exasperated conqueror. [Illustration: SO-CALLED SARCOPHAGUS OF ALEXANDER PRESERVED IN CONSTANTINOPLE]