 A treaty between the Romans and the Samnites in 354 BC set a southern border with Samnium, which ran from the middle of the Liris River valley to southern Campania.In 334 BC, the Romans advanced into the Liris valley which the Samnites found that to be an unacceptable intrusion by Rome, but were too preoccupied to respond at the time as they were involved in a conflict with the Greek colony of Tarentum and its ally, Alexander of Epirus.In 328 BC the Romans established a colony at Fregellae on the Liris River and another at Cales.