Assessing the failures of Charlemagne’s rule, historian F.L. Ganshof famously argued that “[Charlemagne] left the Frankish state as he found it.”
In my opinion, F.L. Ganshof meant that Charlemagne left his empire weak and divided, just like before he became the Frankish king. His failures were obviously seen in his empire’s government and economy.
While Charlemagne “raised the intellectual standards of his realm,” the economy of his empire remained fragile. They only had a few centers of craft and production, and industry was minimal. It appears that he also depended on wars to increase his resources. “Regular flows of plunder and tribute were a central facet of Frankish political expansion in the eighth century, and fuelled a flow of high-status gifts, whose impact on contemporaries is clear from the awestruck descriptions of the wagons laden with fabulous riches plundered from the Avars returning to Aachen.”
In addition, Charlemagne conquered many territories but he failed to manage them. His people were “separated from one another by custom, culture, language, and religion.” Even though his goal of conquest was to unify by expanding Christianity, the “Carolingians were never able to balance the diversity of their empire.” He had the Saxons forcefully baptized and had thousands executed in one day, yet some of them still rebelled.
His empire expanded vastly that communication became very difficult. He had to rely on his dukes, margraves, and counts just like his predecessors, but not all of them were truly loyal. These authorities “had to be entrusted with broad powers over royal tribunals, taxation systems, and military recruitment in their counties.” Despite Charlemagne’s predominant power, there were still local and regional violence like plundering raids and highway robberies. During the final decade of his life, disaffection and rebellion arose and “brought political chaos to the reign of his son and heir, Louis the Pious.”
Charlemagne continued many traditions that probably weren’t best to follow anymore, since his empire underwent cultural and intellectual renaissance. The family practice of dividing succession eventually became the primary reason of Carolingian empire’s fall.