Stringent orders were issued to the inhabitants of the districts through which Hannibal would march on his way to Rome to destroy their crops, drive off their cattle, and take refuge in the fortified towns. Servilius was appointed to the command of the Roman fleet, and ordered to oppose the Carthaginians at sea. The army of Fabius was now greatly superior to that of Hannibal, but was inferior in cavalry. He had, moreover, the advantage of being in a friendly country, and of being provisioned by the people through whose country he moved, while Hannibal was obliged to scatter his army greatly to obtain provisions.
Fabius moved his army until within six miles of that of Hannibal, and then took up his position upon the hills, contenting himself with watching from a distance the movements of the Carthaginians. Hannibal marched unmolested through some of the richest provinces of Italy till he descended into the plain of Campania. He obtained large quantities of rich booty, but the inhabitants in all cases held aloof from him, their belief in the star of Rome being still unshaken in spite of the reverses which had befallen her.
Fabius followed at a safe distance, avoiding every attempt of Hannibal to bring on a battle.
The Roman soldiers fretted with rage and indignation at seeing the enemy, so inferior in strength to themselves, wasting and plundering the country at their will. Minucius, the master of horse and second in command, a fiery officer, sympathized to the full with the anger of the soldiers, and continually urged upon Fabius to march the army to the assault, but Fabius was immovable. The terrible defeats which Hannibal had inflicted upon two Roman armies showed him how vast would be the danger of engaging such an opponent unless at some great advantage.
Such advantage he thought he saw when Hannibal descended into the plain of Campania. This plain was inclosed on the south by the river Vulturnus, which could be passed only at the bridge at Casilinum, defended by the Roman garrison at that town, while on its other sides it was surrounded by an unbroken barrier of steep and wooded hills, the passes of which were strongly guarded by the Romans.
After seeing that every road over the hills was strongly held by his troops, Fabius sat down with his army on the mountains, whence he could watch the doings of Hannibal's force on the plains. He himself was amply supplied with provisions from the country in his rear, and he awaited patiently the time when Hannibal, having exhausted all the resources of the Campania, would be forced by starvation to attack the Romans in their almost impregnable position in the passes.
Hannibal was perfectly aware of the difficulties of his position. Had he been free and unencumbered by baggage he might have led his army directly across the wooded mountains, avoiding the passes guarded by the Romans, but with his enormous trail of baggage this was impossible unless he abandoned all the rich plunder which the army had collected. Of the two outlets from the plain, by the Appian and Latin roads which led to Rome, neither could be safely attempted, for the Roman army would have followed in his rear, and attacked him while endeavouring to force the passages in the mountains.
The same objection applied to his crossing the Vulturnus. The only bridge was strongly held by the Romans, and the river was far too deep and rapid for a passage to be attempted elsewhere with the great Roman army close at hand. The mountain range between the Vulturnus and Cades was difficult in the extreme, as the passes were few and very strongly guarded, but it was here that Hannibal resolved to make the attempt to lead his army from the difficult position in which it was placed. He waited quietly in the plain until the supplies of food were beginning to run low, and then prepared for his enterprise.
An immense number of cattle were among the plunder. Two thousand of the stoutest of these were selected, torches were fastened to their horns, and shortly before midnight the light troops drove the oxen to the hills, avoiding the position of the passes guarded by the enemy. The torches were then lighted, and the light troops drove the oxen straight up the hill. The animals, maddened by fear, rushed tumultuously forward, scattering in all directions on the hillside, but, continually urged by the troops behind them, mounting towards the summits of the hills.
The Roman defenders of the passes, seeing this great number of lights moving upwards, supposed that Hannibal had abandoned all his baggage, and was leading his army straight across the hills. This idea was confirmed by the light troops, on gaining the crest of the hills, commencing an attack upon the Romans posted below them in the pass through which Hannibal intended to move. The Roman troops thereupon quitted the pass, and scaled the heights to interrupt or harass the retreating foe.