Goths and continued with Huns, Avars, Bulgars, Slavs, Pechenegs, Hungarians and Cumans. The invasions of Slavs were the most thoroughgoing, and they partially reduced the Romanic element in the Balkans. The invasion of the Turks and conquest of Constantinople in 1453 marked the end of the empire. 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—Aromanian, Istro-Romanian, and Megleno-Romanian—during the ninth and tenth centuries, when the Romanians (sometimes called Vlachs or Wallachians) emerged as a people. Early Romance 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. Clear evidence of some levels of change is found in the Reichenau Glosses, an eighth-century compilation of about 1,200 words from the fourth-century Vulgate of Jerome that had changed in phonological form or were no longer normally used, along with their eighth-century equivalents in proto-Franco-Provençal. The following are some examples with reflexes in several modern Romance languages for comparison: In all of the above examples, the words appearing in the fourth century Vulgate are the same words as would have been used in Classical Latin of c. 50 BC. It is likely that some of these words had already disappeared from casual speech by the time of the Glosses; but if so, they may well have been still widely understood, as there is no recorded evidence that the common people of the time had difficulty understanding the language. By the 8th century, the situation was very different. During the late 8th century, Charlemagne, holding that "Latin of his age was by classical standards intolerably corrupt", successfully imposed Classical Latin as an artificial written vernacular for Western Europe. Unfortunately, this meant that parishioners could no longer understand the sermons of their priests, forcing the Council of Tours in 813 to issue an edict that priests needed to translate their speeches into the rustica romana lingua, an explicit acknowledgement of the reality of the Romance languages as separate languages from Latin. By this time, and possibly as early as the 6th century according to