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