Terracina occupied a position of notable strategic importance: it is located at the point where the Volscian Hills (an extension of the Lepini Mountains) reach the coast, leaving no space for passage between them and the sea, on a site commanding the Pontine Marshes (, "a city surrounded by marshes", as Livy called it) and also possessing a small harbour.According to the "Encyclopædia Britannica" Eleventh Edition, During the 600s BC, it joined the Etruscan League of twelve cities. In 509 BC Terracina was already under Roman supremacy as reported in the 1st treaty between Rome and Carthage. It was soon re-occupied by the Volsci and was not included in the list of the Latin league of 499 BC. In 406 it was recaptured by the Romans then lost in 402 and recovered in 400, unsuccessfully attacked by the Volsci in 397, and finally secured by the establishment of a colony of Roman citizens in 329 BC as .