Titus Livius (Livy), The History of Rome, Book 43
Alfred C. Schlesinger, Ph.D., Ed.

18. Perseus did not dare to leave the limits of Macedonia at the outset of winter, for fear that at some point the Romans might raid his undefended realm. [2] About the winter solstice, however, when [p. 65]the depth of snow makes the mountains¹ impassable² from Thessaly, he thought that here was an opportunity to shatter the hopes and spirits of his neighbours, so that no danger might arise from them while his attention was turned toward the campaign against the Romans. On the side of Thrace Cotys assured peace, as did Cephalus on the side of Epirus³ by his sudden desertion of the Romans, while the recent campaign had subdued the Dardani. [3] Perceiving then that the only quarter hostile to Macedonia was that which allowed access from Illyricum, where the Illyrians themselves were restless and were providing the Romans with an approach, and that if he conquered the nearest Illyrians, he might also entice King Gentius, who had long been wavering, into an alliance, Perseus set [4??] out with ten thousand infantry, some of whom were phalanx-men,⁴ two thousand light troops, and five hundred cavalry, and reached Stuberra. [5] Thence, taking grain for a number of days and ordering equipment for besieging cities to follow, on the third day he pitched camp by Uscana⁵ —which is the largest city of the Penestian region —but sent, before bringing an attack to bear, men to test the mood, now of the commanders of the garrison, now of the townspeople. [6] For there was in the city, along with the young men of the Illyrians, a Roman garrison. After the messengers reported [p. 67]nothing in the way of terms, Perseus began to press⁶ the siege and tried to capture the city with a surrounding attack. [7] Although without interruption through day and night relay of men after relay here brought ladders against the walls, and there fire against the gates, nevertheless, the defenders of the city withstood this tempest, because they had [8??] hopes that the Macedonians could not longer endure the violence of winter in the open, and that the lull in the Roman campaign would not long permit the king to linger. However, after they saw sheds being brought up and towers raised, their determination was overcome. [9] For apart from the fact that they were not equally matched against the assault, there was no supply even of grain or of anything else in the city, as was natural when the siege was unexpected. [10] And so, since there was no hope of holding out, Gaius Carvilius of Spoletium and Gaius Afranius were sent from the Roman garrison to request of Perseus, first, that he should permit them to depart under arms and carrying their possessions with them, and next, if they failed to obtain this, that they should at least receive assurances of life and freedom. The king's generosity was greater in promise than in performance; for after bidding them to depart carrying their possessions with them, he deprived them first of their arms, then of their freedom. [11] After the Romans had left the city, both the force of Illyrians —there were five hundred of them —and the people of Uscana surrendered themselves and their city.