Prior to the Roman conquest, a large part of Western Europe had adopted the newly developed La Tène culture. As the Roman domain expanded, a cultural and linguistic division appeared between the mainly Greek-speaking eastern provinces, which had formed the highly urbanized Hellenistic civilization, and the western territories, which in contrast largely adopted the Latin language. This cultural and linguistic division was eventually reinforced by the later political east–west division of the Roman Empire. The Western Roman Empire and the Eastern Roman Empire controlled the two divergent regions between the 3rd and the 5th centuries.