Alexander, on receiving this intelligence, marched rapidly against the Kathaians, and on the second day after he had left the river Hydraôtês arrived at a city named Pimprama, belonging to an Indian race called the Adraïstai,[127] which surrendered on terms of capitulation. Alexander gave his troops rest the next day, and on the third day advanced to Sangala, where the Kathaians and the neighbouring tribes that had joined them were mustered before the city, and drawn up in battle-order on a low hill, which was not on all sides precipitous. They lay encamped behind their waggons, which, by encircling the hill in three rows, protected the camp with a triple barricade. Alexander, on perceiving the great number of the barbarians, and the nature of the position they occupied, drew up his army in the order which seemed best suited to the circumstances, and at once despatched against them the horse-archers just as they were, with orders to ride along and shoot at the Indians from a distance, so as not only to prevent them from making a sortie before his own dispositions should be completed, but to wound them within their stronghold even before the battle began. Upon his right wing he posted the corps of horseguards and the cavalry regiment of Kleitos, next to these the hypaspists, and then the Agrianians. The left wing he assigned to Perdikkas, who commanded his own cavalry regiment and the battalions of the footguards. The archers he formed into two bodies, and placed them upon each wing. While he was making these dispositions the infantry and cavalry which formed the rearguard arrived upon the field. This cavalry he divided in two parts, and led one to each wing, and with the infantry that had arrived he closed up the ranks of the phalanx more densely. Then he took the cavalry which had been drawn up on the right and advanced against the waggons ranged on the left wing of the Indians, where the position seemed easier to assault, and where the waggons were not so closely packed together. _Chapter XXIII.—Alexander drives the Kathaians into Sangala, which he invests on every side_