The two reigns of Pippin the Short and Charlemagne, apart from this Italian intervention which was to have grandiose developments soon, represent a gigantic effort to solve problems that the previous age had left suspended. First of all they finally repelled the Arabs from Septimania; energetic blows were made to Aquitan autonomy so that in 768 when Pippin died, Aquitaine was already in the process of reorganization by means of Frankish accounts and officials. The need to defend the southern border led Charlemagne to a series of military operations south of the Pyrenees, in order to occupy the region between the Pyrenees and the Ebro organizing a military government called the Hispanic March. It was harsher to find a solution to the situation across the Rhine. Pippin had already led expeditions to drive back the Saxons. Charlemagne wanted to reach a definitive solution by subjecting all the Saxon tribes. About three decades of bitter wars took place, because on the other hand it was necessary to secure the border of Elba against the Slavic tribes breaking through from the east; Charles therefore had to overthrow the empire of the Avars, nestled in the Hungarian region, and organize between the Danube and the western Alps a bulwark against the barbarians of the East in the so-called Marca d’Oriente (Austria).
At the end of the century VIII the kingdom of the Franks had an enormous extension: it spread from the old Roman Gaul to the point of totally dominating the Germanic and Italian regions, partially the Iberian ones. The Frankish element had borne, if not exclusively, certainly to a large extent, the weight of all these wars. Apparently the burden deriving from it was not felt, because the ecclesiastical and military aristocracy was on a par with the dynasty dominated by imperialist conceptions, widespread due to relations with Roman Italy and under the impression of the great conquests. These conceptions ended up triumphing with the support of the papacy which speculated on the reconstruction of a Western Christian empire. Thus in the year 800 Charlemagne became Roman emperor, coonesting with such dignity both the conquests,
According to militarynous.com, these imperialist conceptions, however, were not in contrast with the particularist conceptions that remained in the Frankish tradition. Roman Empire yes, but in the service of the Frankish people who considered themselves the master of the empire: and Charlemagne while he called himself emperor, continued to use the title of rex Francorum. In addition, Charles continued to keep his old center of Aachen and the national dress. No concessions were made to Roman theories: Charles entrusted the recognition of his successor to a Frankish assembly; for the coronation of Ludovico he ignored the papal rights and the precedent of the year 800, and, regardless of the imperial dignity, in the year 806 he proceeded to the division of his states, with the old criterion of Clovis and Clotaire.
France, kingdom of the Franks, Roman empire of the Franks are three political conceptions that in the age of Charlemagne and his immediate successors are unable to coincide or to clearly distinguish themselves. Italy therefore remains outside, with its well-marked individuality: even Charlemagne said he was king of the Franks and the Lombards. Instead, from the Schelda to the Ebro the whole country is the kingdom of the Franks; it already seems to be tending to be confused with France. In 806, the division made by Charles ignores France: Pippin had Italy, Bavaria, Alamannia; Ludovico, Burgundy, Aquitaine, Gascony; Charles, Austrasian France and Neustria, part of Burgundy, Friesland, Saxony, Thuringia. Carlo was the eldest son: he was in the villages of the Frankish tradition. This division corresponded to that of 781, when Pope Adrian had crowned Pepin king of Italy, Ludovico king of Aquitaine. Charles thought about regulating the relations of his three sons to prevent civil wars, remembering his brother, uncle and all the Merovingians. Fraternal and moral union, based on the integrity of the Frankish kingdom for the firstborn. But under Louis the Pious a bitter battle was fought between the partisans of imperial unity and the supporters of the territorial division, which respected the empire only as a very high moral dignity. Imperial unity was proclaimed in the partition of 817, collapsed in the Treaty of Verdun of 843. Lothair had Italy, Provence, part of Burgundy, Alsace and the Frankish countries, between the Rhine on one side and the line of the Saone on the other, of the Meuse and the Scheldt; Charles had all the villages west of the Meuse as far as the ocean; Ludovico had the countries to the east of the kingdom. Division that had no theoretical basis. In fact, it did not correspond to a distinction of races, to an affirmation of nations. The empire remained as a moral unit, no longer as a territorial unit.