Philip at this time, now that he saw the greater part of his army drawn up outside the entrenchment, advanced with the peltasts and the right wing of phalanx, ascending energetically the slope that led to the hills
and giving orders to Nicanor, who was nicknamed the elephant, to see that the rest of his army followed him at once.
When the leading ranks reached the top of the pass, he wheeled to the left, and occupied the summits above it; for, as the Macedonian advanced force had pressed the Romans for a considerable distance down the opposite side of the hills, he found these summits abandoned.
While he was still deploying his force on the right his mercenaries appeared hotly pursued by the Romans.
For when the heavy-armed Roman infantry had joined the light infantry, as I said, and gave them their support in the battle, they availed themselves of the additional weight thus thrown into the scale, and pressing heavily on the enemy killed many of them.
When the king, just after his arrival, saw that the light infantry were engaged not far from the hostile camp he was overjoyed, but now on seeing his own men giving way in their turn and in urgent need of support, he was compelled of go to their assistance and thus decide the whole fate of the army on the spur of the moment, although the greater portion of the phalanx was still on the march and approaching the hills.
Receiving those who were engaged with the enemy, he placed them all, both foot and horse, on his right wing and ordered the peltasts and that part of the phalanx he had with him to double their depth and close up towards the right.
Upon this being done, the enemy being now close upon them, orders were sent out to the men of the phalanx to lower their spears and charge, while the light infantry were ordered to place themselves on the flank.
At the same moment Flamininus, having received his advanced force into the gaps between the maniples, fell upon the enemy.
Walbank Commentary