Titus Livius (Livy), The History of Rome, Book 21
D. Spillan, A.M., M.D., Cyrus Evans, Ed.

32. Publius Cornelius the consul, about three days after Hannibal moved from the bank of the Rhone, had come to the camp of the enemy, with his army drawn up in square, intending to make no delay in fighting: [2] but when he saw the fortifications deserted, and that he could not easily come up with them so far in advance before him, he returned to the sea and his fleet, in order more easily and safely to encounter Hannibal when descending from the Alps. [3] But that Spain, the province which he had obtained by lot, might not be destitute of Roman auxiliaries, he sent his brother Cneius Scipio with the principal part of his forces against [4??] Hasdrubal, not only to defend the old allies and conciliate new, but also to drive Hasdrubal out of Spain. [5] He himself, with a very small force, returned to Genoa, intending to defend Italy with the army which was around the Po. From the Druentia, by a road [6??] that lay principally through plains, Hannibal arrived at the Alps without molestation from the Gauls that inhabit those regions. [7] Then, though the scene had been previously anticipated from report, (by which uncertainties are wont to be exaggerated,) yet the height of the mountains when viewed so near, and the snows almost mingling with the sky, the shapeless huts situated on the cliffs, the cattle and beasts of [p. 731]burden withered by the cold, the men unshorn and wildly dressed, all things, animate and inanimate, stiffened with frost, and other objects more terrible to be seen than described, renewed their alarm. [8] To them, marching up the first acclivities, the mountaineers appeared occupying the heights over head; who, if they had occupied the more concealed valleys, might, by rushing out suddenly to the attack, have occasioned great flight and havoc. [9] Hannibal orders them to halt, and having sent forward Gauls to view the ground, when he found there was no passage that way, he pitches his camp in the widest valley he could find, among places all rugged and precipitous. Then, having learned from the same Gauls, when they had mixed in conversation with the mountaineers, from whom they differed little in [10??] language and manners, that the pass was only beset during the day, and that at night each withdrew to his own dwelling, he advanced at the dawn to the heights, as if designing openly and by day to force his way through the defile. [11] The day then being passed in feigning a different attempt from that which was in preparation, when they had fortified the camp in the same place where they had halted, as soon as he perceived that the mountaineers had descended from the heights, and that the guards were withdrawn, having [12??] lighted for show a greater number of fires than was proportioned to the number that remained, and having left the baggage in the camp, with the cavalry and the principal part of the infantry, he himself with a party of light-armed, [13??] consisting of all the most courageous of his troops, rapidly cleared the defile, and took post on those very heights which the enemy had occupied.