The West from the Peace of Hannibal to the Close of the Third Period Subjugation of the Valley of the Po The war waged by Hannibal had interrupted Rome in the extension of her dominion to the Alps or to the boundary of Italy, as was even now the Roman phrase, and in the organization and colonizing of the Celtic territories.

It was self-evident that the task would now be resumed at the point where it had been broken off, and the Celts were well aware of this.

In the very year of the conclusion of peace with Carthage (553) hostilities had recommenced in the territory of the Boii, who were the most immediately exposed to danger; and a first success obtained by them over the hastily-assembled Roman levy, coupled with the persuasions of a Carthaginian officer, Hamilcar, who had been left behind from the expedition of Mago in northern Italy, produced in the following year (554) a general insurrection spreading beyond the two tribes immediately threatened, the Boii and Insubres.
The Ligurians were driven to arms by the nearer approach of the danger, and even the youth of the Cenomani on this occasion listened less to the voice of their cautious chiefs than to the urgent appeal of their kinsmen who were in peril.

Of "the two barriers against the raids of the Gauls," Placentia and Cremona, the former was sacked--not more than 2000 of the inhabitants of Placentia saved their lives--and the second was invested.

In haste the legions advanced to save what they could.