The name derives from Latin, because Ladin is originally a Vulgar Latin language left over from the Romanized Alps. Ladin is often attributed to be a relic of Vulgar Latin dialects associated with Rhaeto-Romance languages. Whether a proto-Romance language ever existed is controversially discussed amongst linguists and historians, a debate known as "Questione Ladina". Starting in the 6th century, the Bavarii started moving in from the north, while from the south Gallo-Italic languages started pushing in, which further shrank the original extent of the Ladin area. Only in the more remote mountain valleys did Ladin survive among the isolated populations.