The ardor for annexing the Far Eastern division of the Persian Empire to his rule spurred Alexander on, now that the rebellion of Bessus had so unexpectedly failed. He purposed to make, not the Oxus, but the Tanais his frontier on the northeast. The resistance seemed easily overcome; the seven strongholds of the Sogdians were occupied, and on the banks of the Jaxartes, or Tanais, at a point which is the gate of communication between southwestern Asia and China, the pass over the Tian-shan mountains, Alexander set the boundary of his conquests in this direction, by founding a new city called Alexandria the Ultimate, in later days Khodjend. While he was planning his new town, the country rose in revolt, for the chieftains of Sogdiana had no mind to lose their freedom. The small Macedonian garrisons left in the strongholds a short time before were overpowered, and the city of Maracanda was being besieged. The news of the revolt had spread far and wide, and the various Scythian tribes were hurrying to join in driving out the invaders. Alexander quickly recovered the strongholds, burning five of them, but at Cyropolis there was stout resistance, and he received a wound. The inhabitants of all were removed and forcibly transplanted as citizens of the new Alexandria. (328 B.C.) It was not possible to go to the rescue of Maracanda because of the threatening attitude of the Scythian tribes, who were preparing to descend upon Alexandria, which was only separated from them by the river Tanais. The danger of being rushed by these barbarous hordes was imminent. The new city, therefore, was made capable of resistance; in the short period of twenty days it was surrounded with walls of unburnt clay. But Alexander determined also to strike terror by aggressive action. He brought up to the banks of the river engines which threw stones and darts among the enemy and forced them to retreat from the stream. Then the Greek army crossed, and the Scythians were soon routed. The king, with his cavalry, pursued them some distance in their own territory. The heat was intense and Alexander was made dangerously ill by drinking the water along the line of march. On his recovery he had to deal with a difficult revolt in Sogdiana, again led by Spitamenes, who had figured in the previous uprising and who this time had succeeded in cutting off a detachment of Macedonian troops sent in pursuit of him. It is recounted that the fear of a disaster made such a serious impression on the conqueror that he covered the distance to Samarcand, over 150 miles, in three days. Spitamenes did not wait to try conclusions with the Greeks, but abandoned the siege, drawing off hurriedly in a westward direction, closely pursued by Alexander.