Titus Livius (Livy), The History of Rome, Book 28
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

¹ of infantry and three troops of cavalry on each wing, and with skirmishers in addition, they led at a rapid pace against the enemy, while the rest followed them obliquely. [2] In the centre was a curve where the Spanish units were more slowly advancing.

[3] By this time the wings were already engaged, while the main strength of the enemy's line, the veteran Carthaginians and Africans, had not yet come within range, and did not dare to dash towards the wings to help the combatants, for fear of exposing the centre to the enemy directly advancing. [4] The wings were being hard pressed by a double attack; cavalry and light-armed and skirmishers with enclosing wings were charging into their flanks, while the cohorts were pressing them in front, endeavouring to cut off the wings from the rest of the battle-line. XV. And not only was the battle in general far from being evenly matched, but especially because the horde of Baliares and Spanish recruits had been made to face Roman and Latin soldiers. [5] Besides, as the day now wore on their strength also began to fail Hasdrubal's soldiers, who had been surprised by an early morning onslaught and compelled to go out into line in haste before they [p. 65]could take food to sustain them. [6] And Scipio had² deliberately dragged out the day, in order that the battle might be belated. For it was not until the seventh hour that the infantry units³ charged the wings. [7] The battle reached the centre of the lines considerably later, so that the heat of the midday sun and the strain of standing under arms, and at the same time hunger and thirst, weakened their bodies before they engaged the enemy. Accordingly they stood resting on their shields. By this time, in addition to everything else, the elephants also took fright at the skirmishing tactics of cavalry and skirmishers and light-armed and had shifted from the wings into the centre. [8] Weakened therefore in body [9??] and spirit the men retreated, keeping their ranks nevertheless, just as if by order of the general the line was giving way intact.

[10] But when the victors, on seeing that the tide of battle had turned, for that reason charged with more spirit from all sides, and it was not easy to withstand their attack, although Hasdrubal tried to hold his men back and confronted them as they gave way, shouting to them again and again that in the rear there were hills and a safe refuge if they retired slowly. [11] Nevertheless, as fear overcame their respect for him and those nearest to the enemy were falling, at once they faced about and all took to flight. And at first the standard-bearers began to halt at the foot of the hills and to call the soldiers back into their ranks, while the Romans hesitated to advance their line up the hill. Then when the enemy saw the standards coming bravely on, they resumed their flight and were [p. 67]driven panic-stricken into camp. [12] Not far from the⁴ earthwork were the Romans; and by such momentum they would have captured the camp if, after a blazing sun, such as shines out in the midst of clouds heavy with rain, there had not been so extraordinary a downpour that the victors with difficulty retired to their camp, and had not some been beset by scruples also against any further attempt that day. [13] The Carthaginians, although night and pouring rain invited them to needed rest, being weak from exertion and wounds, nevertheless, because fear and danger gave them no time to be idle when the enemy would attack the camp at daybreak, [14??] raised their earthwork by gathering stones from near-by valleys all round, intending to defend themselves by a fortification, since in their arms they would have no sufficient protection. But the desertion of their allies made flight seem safer than delay. [15] Defection began with Attenes, prince of the Turdetani, who deserted with a large force of his tribesmen. Then two fortified towns were handed over with their garrisons to the Roman by their commanders. [16] And for fear the mischief might spread farther, now that men were once disposed to change sides, Hasdrubal moved his camp in the silence of the following night.