Titus Livius (Livy), The History of Rome, Book 42
Evan T. Sage, Ph.D. and Alfred C. Schlesinger, Ph.D., Ed.

51. This conference was held at Pella, in the ancient palace of the Macedonians. “Let us, then,” said Perseus, “wage war, since this seems best, with the kindly help of the gods,” and sending dispatches to his officers he drew all his forces together at Citium, a city of Macedonia. [2] He himself offered a sacrifice of one hundred victims in regal style to Minerva whom they call “Defender of the Folk,”¹ and set out for Citium with a band of wearers of the purple² and attendants. [3] There all the forces of Macedonians and foreign auxiliaries had already assembled. He pitched camp before the city and drew up all the soldiers on the plain; the total of all was forty-three thousand under arms; about half of these were phalanx-men;³ Hippias of Beroea⁴ was their commander. [4] Then there were two thousand chosen from all the force of light infantry⁵ for their strength and the vigour of their youth; this unit the Macedonians called the Guard;⁶ its commanders were Leonnatus and Thrasippus, Eulyestans.⁷ [5] The leader [p. 449]of the other light infantry, about three thousand men,⁸ was Antiphilus of Edessa. The Paeonians from the districts both of the Mountainside⁹ and of the Strymon Valley —these places march with Thrace — and the Agrianes,¹⁰ with an admixture, besides, of Thracian settlers, also supplied a contingent of nearly three thousand. [6] Didas the Paeonian, who had killed young Demetrius,¹¹ had armed and mustered [7] them. There were also two thousand Gauls¹² under arms; their commander was Asclepiodotus from Heraclea of the Sintians; three thousand free Thracians were under their own commander. About an equal number of Cretans followed native leaders, Susus of Phalasarnae and Syllus of [8] Knossus. Leonides too, the Lacedaemonian, commanded five hundred from Greece, a mixed group of men. He was said to be of the royal blood, an exile, condemned by a full council of the Achaeans because of dispatches to Perseus which had been [9] intercepted. Lycon the Achaean was commander of the Aetolians and Boeotians, who amounted in all to not more than five hundred. Of these auxiliaries, made up of so many peoples and tribes, the total under arms came to about twelve thousand. Of cavalry, the king had assembled three thousand from all [10] Macedonia. To Citium had come Cotys,¹³ son of Seuthes, king of the tribe of the Odrysae, with one thousand picked cavalry and about an equal number of [11] infantry. Thus the total of the whole army was thirty-nine thousand infantry and four thousand cavalry. It was generally agreed that, [p. 451]except for the army which Alexander the Great took¹⁴ over to Asia,¹⁵ never had the forces of any Macedonian king been so great.