Alexander, while marching to overtake him, arrived at the Hydraôtês—another Indian river, not less in breadth than the Akesinês, but not so rapid.[123] Over all the country which he overran he planted garrisons in the most suitable places, so that the troops under Krateros and Koinos might, while scouring it far and near for forage, traverse it in safety to join him. He then despatched Hêphaistiôn with a force comprising two divisions of infantry, his own regiment of cavalry and that of Dêmêtrios, and one-half of the archers, into the country of that Pôros who had revolted. He received orders to hand over the country to the other Pôros, and when he had reduced all the independent Indian tribes bordering on the banks of the Hydraôtês, to place these also under the rule of Pôros. He himself then crossed the river Hydraôtês, where he met with none of the difficulties which had attended the passage of the Akesinês. When he was advancing into the country beyond the Hydraôtês he found most of the natives willing to surrender on capitulation, while some met him in arms, and others were captured when attempting to escape and reduced to submission. _Chapter XXII.—Alexander marches against the Kathaians—Takes Pimprama, and lays siege to Sangala_ Alexander meanwhile had learned that the Kathaians[124] and other tribes of independent Indians[125] were preparing to meet him in battle if he invaded their country, and were inviting the neighbouring tribes, which were independent like themselves, to coöperate with them. He learned also that the city near which they meant to engage him was strongly fortified, and was called Sangala.[126] The Kathaians themselves enjoyed the highest reputation for courage and skill in the art of war, and the same warlike spirit characterised the Oxydrakai, another Indian race, and the Malloi, who were also an Indian race, for when shortly before this time Pôros and Abisarês had marched against them with their armies, and had besides stirred up many of the independent Indians against them, they were obliged, as it turned out, to retreat without accomplishing anything at all adequate to the scale of their preparations.