The Hirpini (Latin: ; Greek: ;) were an ancient Samnite people of Southern Italy. While general regarded as having been Samnites, sometimes they are treated as a distinct and independent nation. They inhabited the southern portion of Samnium, in the more extensive sense of that name, roughly the area now known as Irpinia from their name—a mountainous region bordering on Basilicata towards the south, on Apulia to the east, and on Campania towards the west. No marked natural boundary separated them from these neighboring nations, but they occupied the lofty masses and groups of the central Apennines, while the plains on each side, and the lower ranges that bounded them, belonged to their more fortunate neighbors. The mountain basin formed by the three tributaries of the Vulturnus (modern Volturno)—the Tamarus (modern Tamaro), Calor (mod. Calore), and Sabatus (mod. Sabato), which, with their valleys, unite near Beneventum, surrounded on all sides by lofty and rugged ranges of mountains—is the center and heart of their territory. Its more southern portion comprised the upper valley of the Aufidus (modern Ofanto) and the lofty group of mountains where that river takes its rise.