After crossing the river,[701] he left Coenus with his own brigade there upon the bank, with instructions to superintend the passage of the part of the army which had been left behind for the purpose of collecting[702] corn and other supplies from the country of the Indians which was already subject to him. He now sent Porus away to his own abode, commanding him to select the most warlike of the Indians and take all the elephants he had and come to him. He resolved to pursue the other Porus, the bad one, with the lightest troops in his army, because he was informed that he had left the land which he ruled and had fled. For this Porus, while hostilities subsisted between Alexander and the other Porus, sent envoys to Alexander offering to surrender both himself and the land subject to him, rather out of enmity to Porus than from friendship to Alexander. But when he ascertained that the former had been released, and that he was ruling over another large country in addition to his own, then, fearing not so much Alexander as the other Porus, his namesake, he fled from his own land, taking with him as many of his warriors as he could persuade to share his flight. Against this man Alexander marched, and arrived at the Hydraotes,[703] which is another Indian river, not less than the Acesines in breadth, but less in swiftness of current. He traversed the whole country as far as the Hydraotes, leaving garrisons in the most suitable places, in order that Craterus and Coenus might advance with safety, scouring most of the land for forage. Then he despatched Hephaestion into the land of the Porus who had revolted, giving him a part of the army, comprising two brigades of infantry, his own regiment of cavalry with that of Demetrius and half of the archers, with instructions to hand the country over to the other Porus, to subdue any independent tribes of Indians which dwelt near the banks of the river Hydraotes, and to give them also into the hands of Porus to rule. He himself then crossed the river Hydraotes, not with difficulty, as he had crossed the Acesines. As he was advancing into the country beyond the Hydraotes, it happened that most of the people yielded themselves up on terms of capitulation; but some came to meet him with arms, while others who tried to escape he captured and forcibly reduced to obedience. CHAPTER XXII. INVASION OF THE LAND OF THE CATHAEANS.