Lusitanic definitions of "Lusitanic" or "Lusitanian" may include medieval-to-modern Galicia, because the Portuguese people and Galician people share close linguistic and cultural ties, including pre-Roman Celtic ones. Modern Portuguese and the Galician language both derive from medieval Galician-Portuguese, and the term is a cultural classification more than a historic–geographical definition. Although, in Ancient Roman times, the Gallaeci were not part of Lusitania province, what became the Galician-Portuguese language developed from Vulgar Latin in Gallaecia, which comprised what is now Galicia, as well as north Portugal, the center of the development of post-Roman Portuguese culture. Later Portuguese use of the name "Lusitania"
Lusitania 28-24 BC). With Lusitania (and Asturia and Gallaecia), Rome had completed the conquest of the Iberian peninsula, which was then divided by Augustus (25–20 BC or 16-13 BC) into the eastern and northern Hispania Tarraconensis, the southwestern "Hispania Baetica" and the western "Provincia Lusitana". Originally, Lusitania included the territories of Asturia and Gallaecia, but these were later ceded to the jurisdiction of the new "Provincia Tarraconensis" and the former remained as "Provincia Lusitania et Vettones". Its northern border was along the Douro river, while on its eastern side its border passed through "Salmantica" (Salamanca)and "Caesarobriga" (Talavera de la Reina) to