>>18364511all the administrative divisions of the emprie were based on roman ones
all the institutions of the carolingian empire were inherited from rome
what is so difficult to understand?
yes, germany was not a roman province, but that argument is not really relevant, you could just view it as an expansion of roman civilisation beyond the rhine by the will of the germanic people. germanics possessed romanitas, the entire germanic elite spoke latin before the 16th century and so forth.