Ἀλεξάνδρου ἀνάβασις 6.8.7

6.8.7

καὶ ἐν τούτῳ παραγίγνονται αὐτῷ οἵ τε Ἀγριᾶνες καὶ ἄλλαι τάξεις τῶν ψιλῶν, ἃς δὴ ἐπιλέκτους ἅμα οἷ ἦγε, καὶ οἱ τοξόται· οὐ πόρρω δὲ οὐδὲ ἡ φάλαγξ ἐφαίνετο τῶν πεζῶν. καὶ οἱ Ἰνδοὶ ὁμοῦ σφισι πάντων τῶν δεινῶν προσκειμένων ἀποστρέψαντες ἤδη προτροπάδην ἔφευγον ἐς πόλιν ὀχυρωτάτην τῶν πλησίον.

When he came to the river and descried the enemy drawn up on the opposite bank, he plunged at once, just as he was after the march, into the ford, with the cavalry only. When the enemy saw Alexander now in the middle of the stream they withdrew in haste, but yet in good order, from the bank, and Alexander pursued them with the cavalry only. But when the Indians perceived he had nothing but a party of horse with him, they faced round and fought stoutly, being about 50,000 in number. Alexander perceiving that their phalanx was very compact, and his own infantry not on the ground, rode along all round them, and sometimes charged their ranks, but not close at quarters. Meanwhile the Agrianians and other battalions of light-armed infantry, which consisted of picked men, were running on to join along with the archers, while the phalanx of infantry was showing in sight at no great distance off. As they were threatened at once with so many dangers, the Indians wheeled round, and with headlong speed fled to the strongest of all the cities that lay near. Alexander killed many of them in the pursuit while those who escaped to the city were shut up within its walls. At first, therefore, he surrounded the place with his horsemen as soon as they came up from the march.