What Enabled the Roman Empire to Become Powerful and Expand?

Some of the factors that enabled the Roman Empire to expand and become the most powerful force in the Western World during its time were the efficient use of its resources, the ability to construct dependable fortifications, bridges, ports and roads, the political tactic of bringing conquered peoples into its governing and territorial expansion programs, a professional military and a strong and often autocratic centralized ruling body. Although the Romans absorbed many elements of the previous Greek civilization, the structure of the Roman Empire was less dependent on the cooperation of rival city-states than the Greeks were.

By the middle of the 2nd century B.C., Rome was able to defeat Carthage, its major rival for control over the Mediterranean area. The Roman Empire then expanded to its peak territorial range in 117 A.D., which encompassed an area consisting of what are now about 40 modern countries and included a population estimated to be as high as 70 million people.