Titus Livius (Livy), The History of Rome, Book 21
Benjamin Oliver Foster, Ph.D., Ed.

34. They came next to another canton, thickly settled for a mountain district. There, not by open fighting, but by his own devices, trickery and deception, Hannibal was all but circumvented. [2] [p. 101]The elder headmen of the strongholds waited on¹ him, as a deputation, and said that, taught by other men's misfortunes —a useful warning —they preferred to experience the friendship of the Phoenicians rather than their might; [3] they were ready, therefore, to carry out his orders, and they requested him to accept provisions and guides and also hostages as a guarantee of good faith. [4] Hannibal, neither blindly trusting nor yet repulsing them, lest, being spurned, they might become openly hostile, returned a friendly answer, accepted the proffered hostages, and used the supplies, which they had brought down, themselves, to the road. But he drew up his column, before following their guides, by no means as though for a march through a friendly country. [5] The van was made up of elephants and cavalry; he himself, with the main strength of the infantry, came next, looking warily about him and watching everything. [6] When they had got to a narrow place, which was overhung on one side by a ridge, the tribesmen rose up on every quarter from their ambush and assailed them, front and rear, fighting hand to hand and at long range, and rolling down huge boulders on the marching troops. [7] The rear-guard bore the brunt of the attack, and as the infantry faced about to meet it, it was very evident that if the column had not been strengthened at that point, it must have suffered a great disaster in this pass. [8] Even so, they were in the utmost peril and came near destruction. For while Hannibal was hesitating to send his division² down into the defile, since he had no troops left to secure the rear of the infantry, as he himself [p. 103]secured that of the horse, the [9??] mountaineers rushed³ in on his flank, and breaking through the column, established themselves in the road, so that Hannibal spent one night without cavalry or baggage.