Final answer:
As Charlemagne became the sole ruler, the Frankish Empire was divided, leading to instability and fragmentation. Charlemagne's global activities and reforms could not prevent the quick decline of the Carolingian dynasty after his death, which eventually led to the rise of feudalism.
Step-by-step explanation:
Charlemagne's Rise and the Transformation of the Franks
As Charlemagne became the sole ruler of the Frankish kingdom, the empire continued to undergo significant changes. The Frankish Empire was divided into three regions: the Kingdom of the West Franks, the Kingdom of the East Franks, and Lotharingia, leading to instability and further conflicts among the successors of Louis the Pious. Charlemagne's vision of resurrecting the Roman Empire as a Christian state led by Germanic leaders began to falter, particularly due to the Frankish succession law which dictated the division of lands among sons, causing a fragmentation of power.
Charlemagne's global vision included correspondence with the Byzantine rulers and trade with the Abbasid caliph. However, the Carolingian dynasty, to which Charlemagne belonged, lasted only a short time after his death due to the lack of effective succession laws and bureaucracy. The origin of 'Germany' can be traced back to the Kingdom of East Francia, which separated from Charlemagne's legacy.
Charlemagne was not just a king but an empire builder who integrated various Germanic groups under his rule, essentially creating an empire that included France, Germany, northern Italy, parts of Spain, and central Europe. Despite his efforts to reorganize the government and initiate a Carolingian Renaissance in learning and church reform, the stability of his empire was challenged after his death, setting the stage for the rise of feudalism.