Abstract (Crisis of authority or inauguration of a new order? The fragmentation of the Carolingian Empire and the birth of the territorial principalities of the Midi): The Strasbourg Oaths, a monument to the Romance language, and the Treaty of Verdun concluded a year later, mark the beginning of the fragmentation of the Carolingian Empire, united half a century earlier by Charlemagne. Thus began a long period of imperial disintegration, which would not leave languages, cultures, and identities intact. While interpretations vary, ranging from a failed contractual monarchy project under Charles the Bald, King of Western France and late Emperor, to the opposition between a supposed center and its peripheries, case studies of the exercise of power and the change of empire are less frequent. Our paper aims to present the process of disintegration in the case of territorial principalities of the South: the County of Toulouse, and the County of Barcelona. Their history reflects the weakening of an old power and the emergence of new ones. Crisis, solution, or progress, the approaches depend on chronological a priori: what may be a crisis of the previous order, seems a salutary gestation for the one that follows. However, every crisis has its logic: in our case, it will reside in an amalgam of barbaric traditions, a desire for administrative unification, and limits of real power.