Final answer:
Some may not consider the Holy Roman Empire a 'true' empire due to the lack of centralized imperial power, which led to a decentralized and fragmented political structure after Charlemagne's reign.
Step-by-step explanation:
The area once ruled by Charlemagne in the 9th century CE, known as the Holy Roman Empire, might not be considered a 'true' empire by some due to C. the inability for the emperor to have centralized power to unite diverse peoples with unified authority. Charlemagne's empire, which at its height stretched from northern Spain to Bohemia, was a rare moment of unity in Western Europe. After Charlemagne's reign, the empire became fragmented and decentralized, comprising several autonomous regions and kingdoms, and lacking the centralized authority typically seen in empires.
Each kingdom within the empire was a coalition of independent territories, and the emperor was elected by a select group of princes known as electors, rather than through a hereditary system. This electoral system, combined with the lack of a common currency, legal structure, or representative assembly, contributed to the Holy Roman Empire's patchwork, decentralized nature. Moreover, the emperor's power was often beholden to both the electors and the pope, which diluted the imperial authority even further.