As in the case of any Romance language, it is argued that Romanian language derived from Vulgar Latin through a series of internal linguistic changes and because of Dacian or northern Thracian influences on Vulgar Latin in the late Roman era. This influence explains a number of differences between Romanian -Thracian substrate-, French -Celtic substrate-, Spanish -Basque substratum-, Portuguese -Celtic substrate ?- Romanian has no major dialects, perhaps a reflection of its origin in a small mountain region, which was inaccessible but permitted easy internal communication. The history of Romanian is based on speculation because there are virtually no written records of the area from the time of the withdrawal of the Romans around 300 AD until the end of the barbarian invasions around 1300 AD.