Titus Livius (Livy), The History of Rome, Book 25
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

13. While Hannibal was near Tarentum, and [p. 389]both consuls were in Samnium but seemed about to¹ invest Capua, already the Campanians were suffering hunger (the usual hardship of a long investment), because the Roman armies had prevented them from sowing. [2] And so they sent legates to Hannibal, praying that, before the consuls should lead the legions into their lands and all the roads should be blocked by forces of the enemy, he should order grain to be brought from neighbouring places to Capua. [3] Hannibal ordered Hanno to march with his army from the land of the Bruttii over into Campania, and to see to it that the Campanians should have a supply of grain. [4] Hanno set out from the land of the Bruttii with his army, avoided camps of the enemy and the consuls, who were in Samnium, and when he was now nearing Beneventum, pitched camp on high ground three miles from the city itself. [5] Then he ordered grain to be brought into camp from allied peoples of the neighbourhood, among whom it had been garnered in the summer; and he furnished troops to escort the supplies. [6] Then he sent word to Capua, naming a day on which they should appear at the camp to get their grain, after bringing together from the farms on all sides every kind of vehicle and beast of burden. [7] This order was carried out by the Campanians with their usual carelessness and indifference. Little more than four hundred vehicles were sent, and a few beasts of burden besides. For this they were censured by Hanno, that not even hunger, which, as he said, inflames even dumb brutes, could spur their diligence; and another day was assigned for getting their grain with ampler means of transport. [8] When all this was reported, just as it happened, to the Beneventans, they at once [p. 391]sent ten legates to the consuls, the camp of the² Romans being near Bovianum. [9] The consuls, on hearing what was going on near Capua, mutually arranged that one of them should lead his army into Campania, and Fulvius, to whom that assignment had fallen, set out and entered the walls of Beneventum at night. [10] Being near now, he learned that Hanno had gone with a part of his army to procure grain; that through his quaestor grain had been furnished to the Campanians; that two thousand wagons and in addition a mixed and unarmed multitude had arrived; that everything was being done in confusion and excitement, and that the arrangement of the camp and military routine had been broken down by the influx of rustics, foreigners³ at that.

[11] These facts being sufficiently established, the consul ordered the soldiers to make ready their standards and arms, and nothing else, for the following night; they must attack the Carthaginian camp. [12] Setting out at the fourth watch, leaving all their packs and baggage at Beneventum, they reached the camp shortly before daylight and inspired such panic that, if the camp had been placed on level ground, it could undoubtedly have been taken by the first assault. [13] The lofty situation protected it, also the fortifications, which could not be approached from any side except by a steep and difficult slope. [14] At daybreak a great battle blazed up. And the Carthaginians not only defended the earthwork but, as they had the more favourable situation, pushed down the enemy struggling up the steep slope.