Final answer:
The Roman Empire's prosperity was due to a strong military and centralized government, both of which enabled stability, expansive conquests, and efficient management of resources and economy.
Step-by-step explanation:
The prosperity of the Roman Empire can be largely attributed to two pivotal features: a strong military and a centralized government. These components not only provided stability and power but were also vital factors in expanding Rome's territories and generating wealth through conquests.
The military secured vast resources for the empire, including essential grain supplies from regions like Egypt, while serving as a unifying force against external threats.
Concurrently, the centralized government facilitated the coordination and management of the empire's complex economy and bureaucracy, maintaining order and promoting efficiency even amidst the empire's expansive reach. Despite later periods of infighting and tumult, these features were crucial in establishing and maintaining the empire's earlier prosperity.