After intelligence of the battle of Cannae, and a report of the approach of Hannibal, circulated by the discourse of Trebius, the Mopsian party had retired from the city; which was thus given up to the Carthaginian without opposition, and a garrison received into it.
Leaving there all his booty and baggage, and dividing his forces, he orders Mago to receive under his protection the cities of that district which might revolt from the Romans, and to force to defection those which might be disinclined.

He himself, passing through the territory of Campania, made for the lower sea, with the intention of assaulting Naples, in order that he might be master of a maritime city.

As soon as he entered the confines of the Neapolitan territory, he placed part of his Numidians in ambush, wherever he could find a convenient spot; for there are very many hollow roads and secret windings: others he ordered to drive before them the booty they had collected from the country, and, exhibiting it to the enemy, to ride up to the gates of the city.

As they appeared to be few in number and in disorder, a troop of horse sallied out against them, which was cut off, being drawn into an ambuscade by the others, who purposely retreated: nor would one of them have escaped, had not the sea been near, and some vessels, principally such as are used in fishing, observed at a short distance from the shore, afforded an escape for those who could swim.

Several noble youths, however, were captured and slain in that affair.