 The Slavs named the Romance-speaking population Vlachs, while the latter called themselves "Rumân" or "Român", from the Latin "Romanus" The Daco-Roman dialect became fully distinct from the three dialects spoken South of the Danube—Macedo-Romanian, Istro-Romanian, and Megleno-Romanian—during the ninth and tenth centuries, when the Romanians (sometimes called Vlachs or Wallachians) emerged as a people.Over the course of the fourth to eighth centuries, local changes in phonology, morphology, syntax and lexicon accumulated to the point that the speech of any locale was noticeably different from another.In principle, differences between any two lects increased the more they were separated geographically, reducing easy mutual intelligibility between speakers of distant communities.