> This centuries-slow ousting of other languages is the reason behind the Romance family and its wide spread.<p>Keep in mind that Celtic and Latin are both Indo-European languages that split off about 4kya, so 1.5kya-2kya they were a lot closer that Romance languages and Celtic are today, and so what's more likely to have happened is that the Celtic spoken by the Gauls blended with the Latin spoken by the Romans. Germanic and Slavic languages are also Indo-European, so this dynamic worked in much of Europe over the past 2ky.<p>The point is that the other languages, where they were Indo-European, did not get "ousted", rather they blended with Latin.<p>Basque, Finnish, Hungarian -- these are not Indo-European, and those haven't Romanized, which I think helps my thesis :)