Final answer:
One disadvantage of an emperor letting regions make their own decisions is the potential for conflicts and fragmentation within the empire, which can lead to a lack of unity and weaker defense. This was evident in the Roman and Byzantine Empires.
Step-by-step explanation:
One disadvantage of an emperor letting regions make their own decisions about how they govern themselves is that it can lead to conflicts and fragmentation within the empire. When regions have the freedom to govern themselves, they may pursue their own interests rather than working together for the overall benefit of the empire. This can result in a lack of unity, weaker defense against external threats, and economic disparities among the regions.
For example, during the Roman Empire, rival claimants to the throne and the delegation of decision-making to regional powers contributed to the empire's decline and fragmentation.
In the Byzantine Empire, powerful elites within the empire sought to exploit the weaknesses of the ruler, leading to a breakdown in central authority and weakening the army.