Celtic tribes, and settled on the Apennines from above Arezzo and Pisa westward, occupied the region of the sources of the Po.  The eastern portion of the plain north of the Po, nearly from Verona to the coast, was possessed by the Veneti, a race different from the Celts and probably of Illyrian extraction.  Between these and the western mountains were settled the Cenomani (about Brescia and Cremona) who rarely acted with the Celtic nation and were probably largely intermingled with Veneti, and the Insubres (around Milan).  The latter was the most considerable of the Celtic cantons in Italy, and was in constant communication not merely with the minor communities partly of Celtic, partly of non-Celtic extraction, that were scattered in the Alpine valleys, but also with the Celtic cantons beyond the Alps.  The gates of the Alps, the mighty stream navigable for 230 miles, and the largest and most fertile plain of the then civilized Europe, still continued in the hands of the hereditary foes of the Italian name, who, humbled indeed and weakened, but still scarce even nominally dependent and still troublesome neighbours, persevered in their barbarism, and, thinly scattered over the spacious plains, continued to pasture their herds and to plunder.  It was to be anticipated that the Romans would hasten to possess themselves of these regions; the more so as the Celts gradually began to forget their defeats in the campaigns of 471 and 472 and to bestir themselves again, and, what was still more dangerous, the Transalpine Celts began anew to show themselves on the south of the Alps.

Celtic Wars

In fact the Boii had already renewed the war in 516, and their chiefs Atis and Galatas had—­without, it is true, the authority of the general diet—­summoned the Transalpine Gauls to make common cause with them.  The latter had numerously answered the call, and in 518 a Celtic army, such as Italy had not seen for long, encamped before Ariminum.  The Romans, for the moment much too weak to attempt a battle, concluded an armistice, and to gain time allowed envoys from the Celts to proceed to Rome, who ventured in the senate to demand the cession of Ariminum—­it seemed as if the times of Brennus had returned.  But an unexpected incident put an end to the war before it had well begun.  The Boii, dissatisfied with their unbidden allies and afraid probably for their own territory, fell into variance with the Transalpine Gauls.  An open battle took place between the two Celtic hosts; and, after the chiefs of the Boii had been put to death by their own men, the Transalpine Gauls returned home.  The Boii were thus delivered into the hands of the Romans, and the latter were at liberty to expel them like the Senones, and to advance at least to the Po; but they preferred to grant the Boii peace in return for the cession of some districts of their land (518).  This was probably done, because they were just at that time expecting the renewed outbreak of war with Carthage; but, after that war