Still do, Franken is on the one hand a part of Bavaria very insistent on not actually being Bavarian (and they’re right), OTOH a dialect continuum reaching over the Ruhr area up to Flanders and Holland.

Charlemagne was a prince of Austrasia, just another guy in a long dynasty of conquerors but notably the one to conquer Rome (and conversion-by-genocide of the Saxons). Also a lot more Gauls back in the day in France before they went all national state and suppressed minority languages in favour of sounding more Roman.