The position of Casilinum at the junction of the Via Appia and Via Latina, at their crossing of the river Volturnus by a still-existing three-arched bridge, gave the town considerable strategic importance during the Roman Republic.
Remains of this later town have been found at some 25 feet below the modern ground-level, the river-bed having since risen considerably.
[1] During the Second Punic War, Casilinum was first occupied by Quintus Fabius Maximus Verrucosus in 217 BCE.
The town was taken by Hannibal after a gallant defence by troops from Praeneste and Perusia in the winter of 216-215 BCE, but recaptured by Roman forces the following year, thereafter serving the Romans as a base of operations against rebellious Capua.
The period of its final decline or destruction is uncertain but in the 9th century no town was on the spot.