Porsena being repulsed in his first attempt, having changed his plans from a siege to a blockade, after he had placed a garrison in Janiculum, pitched his camp in the plain and on the banks of the Tiber.
Then sending for boats from all parts, both to guard the river, so as not to suffer any provision to be conveyed to Rome, and also to transport his soldiers across the river, to plunder different places as occasion required; in a short time he so harassed the entire country round Rome, that not only every thing else from the country, but even their cattle, was driven into the city, and nobody durst venture thence without the gates.

This liberty of action was granted to the Etrurians, not more through fear than from policy; for Valerius, intent on an opportunity of falling unawares upon a number of them, and when straggling, a remiss avenger in trifling matters, reserved the weight of his vengeance for more important occasions.

Wherefore, to decoy the pillagers, he ordered his men to drive their cattle the next day out at the Esquiline gate, which was farthest from the enemy, presuming that they would get intelligence of it, because during the blockade and famine some slaves would turn traitors and desert.

Accordingly they were informed of it by a deserter, and parties more numerous than usual, in hopes of seizing the entire body, crossed the river.

Then P.Valerius commanded T.Herminius, with a small body of men, to lie concealed two miles from the city, on the Gabian road, and Sp.