How long were the Germanic dialects commonly subsumed under the term "Frankish" spoken by Frankish people in Northern Gaul, and how long did it take until they were completely supplanted by the Romance dialects that would later evolve into French?
EDIT: I'm aware that Alsatian and Dutch are still spoken today, but only in parts of the country that were either not part of France until historically recently or had never had a Romance-speaking majority even before the fall of the Western Roman Empire or the defeat of Syagrius by Hlodwig. I am talking about the Frankish idioms in regions where Franks were a minority.
