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.