In the following year, Publius and Cneius Cornelius Cossus, Numerius Fabius Ambustus, and Lucius Valerius Potitus, being military tribunes with consular power, the Veientian war was commenced on account of an insolent answer of the Veientian senate, who, when the ambassadors demanded restitution, ordered them to be told, that if they did not speedily quit the city and the territories, they should give them what Lars Tolumnius had given them.

The senate, indignant at this, decreed that the military tribunes should, on as early a day as possible, propose to the people the proclaiming war against the Veientians.

When this was first made public, the young men expressed their dissatisfaction.

"That the war with the Volscians was not yet over; that a little time ago two garrisons were utterly destroyed, and that [one of the forts] was with great risk retained.

That there was not a year in which they had not to fight in the field: and, as if they were dissatisfied at the insufficiency of these toils, a new war was now set on foot with a neighbouring and most powerful nation, who were likely to rouse all Etruria." These discontents, first discussed among themselves, were further aggravated by the plebeian tribunes.