The Romans had now no choice but to advance and fight a battle for the recovery of their magazines, for, had they retired, the Apulians, who had already suffered terribly from the war, would, in sheer despair, have been forced to declare for Carthage, while it would have been extremely difficult to continue any longer the waiting tactics of Fabius, as they would now have been obliged to draw their provisions from a distance, while Hannibal could victual his army from the country behind him.  The senate therefore, having largely reinforced the army, ordered the consuls to advance and give battle.

They had under them eight full legions, or eighty thousand infantry and seven thousand two hundred cavalry.  To oppose these Hannibal had forty thousand infantry and ten thousand excellent cavalry, of whom two thousand were Numidians.  On the second day after leaving the neighbourhood of Geronium the Romans encamped at a distance of six miles from the Carthaginians.  Here the usual difference of opinion at once arose between the Roman consuls, who commanded the army on alternate days.  Varro wished to march against the enemy without delay, while Emilius was adverse to risking an engagement in a country which, being level and open, was favourable to the action of Hannibal’s superior cavalry.

On the following day Varro, whose turn it was to command, marched towards the hostile camp.  Hannibal attacked the Roman advanced guard with his cavalry and light infantry, but Varro had supported his cavalry not only by his light troops, but by a strong body of his heavy armed infantry, and after an engagement, which lasted for several hours, he repulsed the Carthaginians with considerable loss.

That evening the Roman army encamped about three miles from Cannae, on the right bank of the Aufidus.  The next morning Emilius, who was in command, detached a third of his force across the river, and encamped them there for the purpose of supporting the Roman foraging parties on that side and of interrupting those of the Carthaginians.

The next day passed quietly, but on the following morning Hannibal quitted his camp and formed his army in order of battle to tempt the Romans to attack; but Emilius, sensible that the ground was against him, would not move, but contented himself with further strengthening his camps.  Hannibal, seeing that the Romans would not fight, detached his Numidian cavalry across the river to cut off the Roman foraging parties and to surround and harass their smaller camp on that side of the river.  On the following morning Hannibal, knowing that Varro would be in command, and feeling sure that, with his impetuous disposition, the consul would be burning to avenge the insult offered by the surrounding of his camp by the Numidians, moved his army across the river, and formed it in order of battle, leaving eight thousand of his men to guard his camp.