Scipio meanwhile held councils of war in Massilia as to the proper mode of occupying the ferries of the Rhone, and was not induced to move even by the urgent messages that came from the leaders of the Celts. He distrusted their accounts, and he contented himself with detaching a weak Roman cavalry division to reconnoitre on the left bank of the Rhone. This detachment found the whole enemy's army already transported to that bank, and occupied in bringing over the elephants which alone remained on the right bank of the stream; and, after it had warmly engaged some Carthaginian squadrons in the district of Avignon, merely for the purpose of enabling it to complete its reconnaissance - the first encounter of the Romans and Phoenicians in this war - it hastily returned to report at head-quarters. Scipio now started in the utmost haste with all his troops for Avignon; but, when he arrived there, even the Carthaginian cavalry that had been left behind to cover the passage of the elephants had already taken its departure three days ago, and nothing remained for the consul but to return with weary troops and little credit to Massilia, and to revile the "cowardly flight" of the Punic leader. Thus the Romans had for the third time through pure negligence abandoned their allies and an important line of defence; and not only so, but by passing after this first blunder from mistaken slackness to mistaken haste, and by still attempting without any prospect of success to do what might have been done with so much certainty a few days before, they let the real means of repairing their error pass out of their hands. When once Hannibal was in the Celtic territory on the Roman side of the Rhone, he could no longer be prevented from reaching the Alps; but if Scipio had at the first accounts proceeded with his whole army to Italy - the Po might have been reached by way of Genoa in seven days - and had united with his corps the weak divisions in the valley of the Po, he might have at least prepared a formidable reception for the enemy. But not only did he lose precious time in the march to Avignon, but, capable as otherwise he was, he wanted either the political courage or the military sagacity to change the destination of his corps as the change of circumstances required. He sent the main body under his brother Gnaeus to Spain, and returned himself with a few men to Pisae.

Hannibal, who after the passage of the Rhone had in a great assembly of the army explained to his troops the object of his expedition, and had brought forward the Celtic chief Magilus himself, who had arrived from the valley of the Po, to address the army through an interpreter, meanwhile continued his march to the passes of the Alps without obstruction. Which of these passes he should choose, could not be at once determined either by the shortness of the route or by the disposition of the inhabitants, although he had no time to lose either in circuitous routes or in combat. He had necessarily to select a route which should be practicable for his baggage, his numerous cavalry, and his elephants, and in which an army could procure sufficient means of subsistence either by friendship or by force; for, although Hannibal had made preparations to convey provisions after him on beasts of burden, these could only meet for a few days the wants of an army which still, notwithstanding its great losses, amounted to nearly 50,000 men. Leaving out of view the coast route, which Hannibal abstained from taking not because the Romans barred it, but because it would have led him away from his destination, there were only two routes of note leading across the Alps from Gaul to Italy in ancient times[3]: the pass of the Cottian Alps (Mont Genevre) leading into the territory of the Taurini (by Susa or Fenestrelles to Turin), and that of the Graian Alps (the Little St. Bernard) leading into the territory of the Salassi (to Aosta and Ivrea). The former route is the shorter; but, after leaving the valley of the Rhone, it passes by the impracticable and unfruitful river-valleys of the Drac, the Romanche, and the upper Durance, through a difficult and poor mountain country, and requires at least a seven or eight days' mountain march. A military road was first constructed there by Pompeius, to furnish a shorter communication between the provinces of Cisalpine and Transalpine Gaul.

The route by the Little St. Bernard is somewhat longer; but after crossing the first Alpine wall that forms the eastern boundary of the Rhone valley, it keeps by the valley of the upper Isere, which stretches from Grenoble by way of Chambery up to the very foot of the Little St. Bernard or, in other words, of the chain of the higher Alps, and is the broadest, most fertile and most populous of all the Alpine valleys. Moreover, the pass of the Little St. Bernard, while not the lowest of all the natural passes of the Alps, is by far the easiest; although no artificial road was constructed there, an Austrian corps with artillery crossed the Alps by that route in 1815. And lastly this route, which only leads over two mountain ridges, has been from the earliest times the great military route from the Celtic to the Italian territory. The Carthaginian army had thus in fact no choice. It was a fortunate coincidence, but not a motive influencing the decision of Hannibal, that the Celtic tribes allied with him in Italy inhabited the country up to the Little St. Bernard, while the route by Mont Genevre would have brought him at first into the territory of the Taurini, who were from ancient times at feud with the Insubres.

So the Carthaginian army marched in the first instance up the Rhone towards the valley of the upper Isere, not, as might be presumed, by the nearest route up the left bank of the lower Isere from Valence to Grenoble, but through the "island" of the Allobroges, the rich, and even then thickly peopled, low ground, which is enclosed on the north and west by the Rhone, on the south by the Isere, and on the east by the Alps. The reason of this movement was, that the nearest route would have led them through an impracticable and poor mountain-country, while the "island" was level and extremely fertile, and was separated by but a single mountain-wall from the valley of the upper Isere. The march along the Rhone into, and across, the "island" to the foot of the Alpine wall was accomplished in sixteen days: it presented little difficulty, and in the "island" itself Hannibal dexterously availed himself of a feud that had broken out between two chieftains of the Allobroges to attach to his interests one of the most important of the chiefs, who not only escorted the Carthaginians through the whole plain, but also supplied them with provisions, and furnished the soldiers with arms, clothing, and shoes. But the expedition narrowly escaped destruction at the crossing of the first Alpine chain, which rises precipitously like a wall, and over which only a single available path leads (over the Mont du Chat, near the hamlet Chevelu). The population of the Allobroges had strongly occupied the pass. Hannibal learned the state of matters early enough to avoid a surprise, and encamped at the foot, until after sunset the Celts dispersed to the houses of the nearest town; he then seized the pass in the night Thus the summit was gained; but on the extremely steep path, which leads down from the summit to the lake of Bourget, the mules and horses slipped and fell. The assaults, which at suitable points were made by the Celts upon the army in march, were very annoying, not so much of themselves as by reason of the turmoil which they occasioned; and when Hannibal with his light troops threw himself from above on the Allobroges, these were chased doubtless without difficulty and with heavy loss down the mountain, but the confusion, in the train especially, was further increased by the noise of the combat. So, when after much loss he arrived in the plain, Hannibal immediately attacked the nearest town, to chastise and terrify the barbarians, and at the same time to repair as far as possible his loss in sumpter animals and horses. After a day's repose in the pleasant valley of Chambery the army continued its march up the Isere, without being detained either by want of supplies or by attacks so long as the valley continued broad and fertile. It was only when on the fourth day they entered the territory of the Ceutrones (the modern Tarantaise) where the valley gradually contracts, that they had again greater occasion to be on their guard. The Ceutrones received the army at the boundary of their country (somewhere about Conflans) with branches and garlands, furnished cattle for slaughter, guides, and hostages; and the Carthaginians marched through their territory as through a friendly land. When, however, the troops had reached the very foot of the Alps, at the point where the path leaves the Isere, and winds by a narrow and difficult defile along the brook Reclus up to the summit of the St. Bernard, all at once the militia of the Ceutrones appeared partly in the rear of the army, partly on the crests of the rocks enclosing the pass on the right and left, in the hope of cutting off the train and baggage. But Hannibal, whose unerring tact had seen in all those advances made by the Ceutrones nothing but the design of procuring at once immunity for their territory and a rich spoil, had in expectation of such an attack sent forward the baggage and cavalry, and covered the march with all his infantry. By this means he frustrated the design of the enemy, although he could not prevent them from moving along the mountain slopes parallel to the march of the infantry, and inflicting very considerable loss by hurling or rolling down stones. At the "white stone" (still called la roche blanche), a high isolated chalk cliff standing at the foot of the St. Bernard and commanding the ascent to it, Hannibal encamped with his infantry, to cover the march of the horses and sumpter animals laboriously climbing upward throughout the whole night; and amidst continual and very bloody conflicts he at length on the following day reached the summit of the pass. There, on the sheltered table-land which spreads to the extent of two and a half miles round a little lake, the source of the Doria, he allowed the army to rest. Despondency had begun to seize the minds of the soldiers. The paths that were becoming ever more difficult, the provisions failing, the marching through defiles exposed to the constant attacks of foes whom they could not reach, the sorely thinned ranks, the hopeless situation of the stragglers and the wounded, the object which appeared chimerical to all save the enthusiastic leader and his immediate staff - all these things began to tell even on the African and Spanish veterans. But the confidence of the general remained ever the same; numerous stragglers rejoined the ranks; the friendly Gauls were near; the watershed was reached, and the view of the descending path, so gladdening to the mountain-pilgrim, opened up: after a brief repose they prepared with renewed courage for the last and most difficult undertaking, - the downward march. In it the army was not materially annoyed by the enemy; but the advanced season - it was already the beginning of September - occasioned troubles in the descent, equal to those which had been occasioned in the ascent by the attacks of the adjoining tribes. On the steep and slippery mountain-slope along the Doria, where the recently-fallen snow had concealed and obliterated the paths, men and animals went astray and slipped, and were precipitated into the chasms. In fact, towards the end of the first day's march they reached a portion of the path about 200 paces in length, on which avalanches are constantly descending from the precipices of the Cramont that overhang it, and where in cold summers snow lies throughout the year. The infantry passed over; but the horses and elephants were unable to cross the smooth masses of ice, on which there lay but a thin covering of freshly-fallen snow, and the general encamped above the difficult spot with the baggage, the cavalry, and the elephants. On the following day the horsemen, by zealous exertion in entrenching, prepared a path for horses and beasts of burden; but it was not until after a further labour of three days with constant reliefs, that the half-famished elephants could at length be conducted over. In this way the whole army was after a delay of four days once more united; and after a further three days' march through the valley of the Doria, which was ever widening and displaying greater fertility, and whose inhabitants the Salassi, clients of the Insubres, hailed in the Carthaginians their allies and deliverers, the army arrived about the middle of September in the plain of Ivrea, where the exhausted troops were quartered in the villages, that by good nourishment and a fortnight's repose they might recruit from their unparalleled hardships. Had the Romans placed a corps, as they might have done, of 30,000 men thoroughly fresh and ready for action somewhere near Turin, and immediately forced on a battle, the prospects of Hannibal's great plan would have been very dubious; fortunately for him, once more, they were not where they should have been, and they did not disturb the troops of the enemy in the repose which was so greatly needed[4].