Broader 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.