The Senones were reckoned allies of Rome; the Romans accordingly sent envoys to them to complain of their furnishing warriors to serve against Rome, and to require the surrender of their captives without ransom.

But by the command of their chieftain Britomaris, who had to take vengeance on the Romans for the death of his father, the Senones slew the Roman envoys and openly took the Etruscan side.

All the north of Italy, Etruscans, Umbrians, Gauls, were thus in arms against Rome; great results might be achieved, if its southern provinces also should seize the moment and declare, so far as they had not already done so, against Rome.

In fact the Samnites, ever ready to make a stand on behalf of liberty, appear to have declared war against the Romans; but weakened and hemmed in on all sides as they were, they could be of little service to the league; and Tarentum manifested its wonted delay.

While her antagonists were negotiating alliances, settling treaties as to subsidies, and collecting mercenaries, Rome was acting.
The Senones were first made to feel how dangerous it was to gain a victory over the Romans.