Arrian

“ But when Alexander had drawn them thus out of the woody glen, he ordered Philotas to take the cavalry which came from upper Macedonia, and to charge their right wing, where they had advanced furthest in their sally. He also commanded Heraclides and Sopolis [6] to lead on the cavalry which came from Bottiaea [7] and Amphipolis against the left wing; while he himself extended the phalanx of infantry and the rest of the horse in front of the phalanx and led them against the enemy's centre. And indeed as long as there was only skirmishing on both sides, the Triballians did not get the worst of it ”

“ His father was Parmenio, the most experienced of Alexander's generals. ↑ Thucydides says (Bk. ii. 96) : "On the side of the Triballians, who were also independent, the border tribes were the Trerians and the Tilatæans, who live to the north of mount Scombrus, and stretch towards the west as far as the river Osoius. This river flows from the same mountains as the Nestus and the Hebrus, an uninhabited and extensive range, joining on to Rhodope." The Osoius is now called Isker. ”

“ Three thousand were slain in the flight; few of them were taken prisoners, both because there was a dense wood in front of the river, and the approach of night deprived the Macedonians of certainty in their pursuit. Ptolemy says, that of the Macedonians themselves eleven horsemen and about forty foot soldiers were killed. ”