Titus Livius (Livy), The History of Rome, Book 23
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

[2] While Hannibal was at the gates —for he again moved his camp from Nuceria to Nola —and [3] the common people of Nola were making fresh plans to revolt, Marcellus, upon the arrival of the enemy, withdrew within the walls, not fearing for his camp, but lest he give the great number who were impatient for it an opportunity to betray the city. [4] Then on both sides they began to form their battle-lines, the Romans before the walls of Nola, the Carthaginians in front of their camp. Thereupon there were small engagements with varying results in the space between the city and the camp, since the commanders [p. 53]wished neither to forbid small numbers who rashly¹ challenged the enemy, nor to give the signal for a general engagement. [5] During this daily guard-duty of the two armies leading citizens of Nola reported to Marcellus that conferences between the common people and the Carthaginians were taking place by night; [6] and that it had been settled that, when the Roman force should be outside the gates and in line, they would plunder their baggage-train and their packs, then close the gates and take possession of the walls, so that, having the control of their affairs and the city in their own hands, they would then admit the Carthaginian instead of the Roman. [7] This being reported to Marcellus, he warmly praised the senators of Nola and resolved to try the fortune of battle before there should be any movement in the city. [8] At the three gates facing the enemy he drew up his army in three sections. He ordered the baggage to bring up the rear, the camp-servants and sutlers and incapacitated soldiers to carry stakes. At the middle gate he posted the pick of the legionaries with the Roman cavalry, at the two gates to right and left the recruits, light-armed and cavalry of the allies. [9] The men of Nola were forbidden to approach the walls and gates, and the forces to be used as reserves were assigned to the baggage, in order to prevent an attack upon it while the legions were fighting. [10] In this formation they were standing inside the gates.

Hannibal, who remained in battle-line under the standards until late in the day, as he had done for several days, at first wondered that the Roman army did not come out of the gate and that there was not one armed man on the walls. [11] Then, supposing [p. 55]the conferences to have been betrayed, and that² inaction was the result of fear, he sent part of his soldiers back to the camp, with orders to bring up in haste to the front line all the equipment for besieging the city. [12] He was quite confident that, if he should press the hesitating, the common people would stir up some outbreak in the city. While they were scattering to their several duties and hastening to the first standards, and the line was advancing to the walls, the gate suddenly opened and Marcellus ordered the trumpets to be sounded and a shout raised; that infantry at first, and then cavalry should sally out against the enemy with all the dash possible. [13] They had carried sufficient panic and confusion into the centre, when Publius Valerius Flaccus and Gaius Aurelius, his lieutenants, sallied out of the two gates on this side and that, to attack the enemy's wings. [14] Sutlers and camp-servants raised another shout, as did the rest of the crowd stationed to guard the baggage so that the shouting gave the sudden impression of a very large army to the Carthaginians, who particularly despised their small numbers. [15] I should hardly venture to assert, what some have affirmed, that 2800 of the enemy were slain, while not more than 500 of the Romans were lost. [16] But whether the victory was on such a scale or less, a very great thing, I rather think the greatest in that war, was accomplished that day. For not to be defeated by Hannibal was a more difficult thing than it was later to defeat him.