After this event, Perseus, now grown fearful, and fallen from his hopes, removed his camp in all haste; he was under the necessity either to stop before Pydna, and there run the hazard of a battle, or disperse his army into cities, and there expect the event of the war, which, having once made its way into his country, could not be driven out without great slaughter and bloodshed. But Perseus, being told by his friends that he was much superior in number, and that men fighting in the defence of their wives and children must needs feel all the more courage, especially when all was done in the sight of their king, who himself was engaged in equal danger, was thus again encouraged; and, pitching his camp, prepared himself to fight, viewed the country, and gave out the commands, as if he designed to set upon the Romans as soon as they approached. The place was a field fit for the action of a phalanx, which requires smooth standing and even ground, and also had divers little hills, one joining another, fit for the motions whether in retreat or advance of light troops and skirmishers. Through the middle ran the rivers Aeson and Leucus, which though not very deep, it being the latter end of summer, yet were likely enough to give the Romans some trouble.
As soon as Aemilius had rejoined Nasica, he advanced in battle array against the enemy; but when he found how they were drawn up, and the number of their forces, he regarded them with admiration and surprise, and halted, considering within himself. The young commanders, eager to fight, riding along by his side, pressed him not to delay, and most of all Nasica, flushed with his late success on Olympus. To whom Aemilius answered with a smile: "So would I do were I of your age; but many victories have taught me the ways in which men are defeated, and forbid me to engage soldiers weary with a long march against an army drawn up and prepared for battle."Then he gave command that the front of his army, and such as were in sight of the enemy, should form as if ready to engage, and those in the rear should cast up the trenches and fortify the camp; so that the hindmost in succession wheeling off by degrees and withdrawing, their whole order was insensibly broken up, and the army encamped without noise or trouble.
When it was night, and, supper being over, all were turning to sleep and rest, on a sudden the moon, which was then at full and high in the heavens, grew dark, and by degrees losing her light, passed through various colours, and at length was totally eclipsed. The Romans, according to their custom, clattering brass pans and lifting up fire-brands and torches into the air, invoked the return of her light;the Macedonians behaved far otherwise: terror and amazement seized their whole army, and a rumour crept by degrees into their camp that this eclipse portended even that of their king. Aemilius was no novice in these things, nor was ignorant of the nature of the seeming irregularities of eclipses- that in a certain revolution of time, the moon in her course enters the shadow of the earth and is there obscured, till, passing the region of darkness, she is again enlightened by the sun. Yet being a devout man, a religious observer of sacrifices and the art of divination, as soon as he perceived the moon beginning to regain her former lustre, he offered up to her eleven heifers. At the break of day he sacrificed as many as twenty in succession to Hercules, without any token that his offering was accepted; but at the one-and-twentieth, the signs promised victory to defenders. He then vowed a hecatomb and solemn sports to Hercules, and commanded his captains to make ready for battle, staying only till the sun should decline and come round to the west, lest, being in their faces in the morning, it should dazzle the eyes of his soldiers. Thus he whiled away the time in his tent, which was open towards the plain where his enemies were encamped.
When it grew towards evening, some tell us, Aemilius himself used a stratagem to induce the enemy to begin the fight; that he turned loose a horse without a bridle, and sent some of the Romans to catch him, upon whose following the beast the battle began. Others relate that the Thracians, under the command of one Alexander, set upon the Roman beasts of burden that were bringing forage to the camp; that to oppose these, a party of seven hundred Ligurians were immediately detached; and that, relief coming still from both armies, the main bodies at last engaged. Aemilius, like a wise pilot, foreseeing by the present waves and motion of the armies the greatness of the following storm, came out of his tent, went through the legions, and encouraged his soldiers. Nasica, in the meantime, who had ridden out to the skirmishers, saw the whole force of the enemy on the point of engaging. First marched the Thracians, who, he himself tells us, inspired him with most terror; they were of great stature, with bright and glittering shields and black frocks under them, their legs armed with greaves, and they brandished, as they moved, straight and heavily-ironed spears over their right shoulders. Next the Thracians marched the mercenary soldiers, armed after different fashions; with these Paeonians were mingled. These were succeeded by a third division, of picked men, native Macedonians, the choicest for courage and strength, in the prime of life, gleaming with gilt armour and scarlet coats. As these were taking their places they were followed from the camp by the troops in phalanx called the Brazen Shields, so that the whole plain seemed alive with the flashing of steel and the glistening of brass; and the hills also with their shouts, as they cheered each other on. In this order they marched, and with such boldness and speed, that those that were first slain died at but two furlongs distance from the Roman camp.