How did Charlemagne manage his state? When and why did Charlemagne’s empire collapse?

How did Charlemagne manage his state? When and why did Charlemagne’s empire collapse? What modern states have emerged on its territory?

Charles was called great because under him the state was sharply expanded due to military campaigns. Charles the Great was a monarch and ruled alone. The state collapsed due to internecine strife within the country, i.e. for the throne. After the collapse of the Frankish empire, several states were formed on its territory, Western In the Frankish territory of France, (the Netherlands or Holland, eastern France, Switzerland and southeastern France) they were located in the middle. In the eastern Frankish territory (mainly Germany, Austria, Slovenia and Croatia.