The Lusitanians (Lusitani, Portuguese: Lusitanos) were a people living in the far west of the Iberian Peninsula, corresponding roughly to Central Portugal (known as central region nowadays) and some areas of modern-day Extremadura and Castilla y Leon, in Spain. After its conquest by the Roman Republic the land was subsequently incorporated as a Roman province named after them (Lusitania). Frontinus mentions Lusitanian leader Viriathus as the leader of the Celtiberians, in their war against the Romans. The Greco-Roman historian Diodorus Siculus attributed them a name of another Celtic tribe: "Those who are called Lusitanians are the bravest of all similar to the Cimbri". The Lusitanians were also called Belitanians, according to the diviner Artemidorus. Strabo differentiated the Lusitanians from the Iberian tribes and thought of them as being Celtiberians who had been known as Oestriminis in ancient times. Lusitanians and Vettones however, based on archeological findings, seem to have been largely pre-Celtic indo-European populations that adopted some Celtic cultural elements by proximity, thus why Strabo might have mistake them as Celtiberians. On the other hand, Pliny the Elder and Pomponius Mela distinguished the Lusitanians from neighboring Celtic groups like the Artabrians in their geographical writings. The original Roman province of Lusitania briefly included the territories of Asturia and Gallaecia, but these were soon ceded to the jurisdiction of the Provincia Tarraconensis in the north, while the south remained the Provincia Lusitania et Vettones. Soon later, Gallaecia would become its own province (taking much of modern Galicia and Northern Portugal). After this, Lusitania's northern border was along the Douro River, while its eastern border passed through Salmantica and Caesarobriga to the Anas (Guadiana) river. Lusitanian War Lusitanian mercenaries fought for Carthage between the years 218 and 201 BC, during the Second Punic War against Rome.