Note 118
M. Bonamy (Mem. de l'Academie des Inscriptions, tom. xxiv. p. 582-670) has ascertained the Lingua Romana Rustica, which, through the medium of the Romance, has gradually been polished into the actual form of the French language. Under the Carlovingian race the kings and nobles of France still understood the dialect of their German ancestors.
The History Of The Decline and Fall Of The Roman EmpireVolume 1Chapter 38