The Rise of the Roman Republic   Chapter 4 shows how Rome grew from a modest settlement to become the center of a great empire. The Romans developed a unique political and military system out of the social conflict known as "the struggle of the orders." The effectiveness of that system, together with a wise political strategy, gave Rome control over the Italian peninsula by 270 BCE But the growth of Roman power threatened Carthage, the leading naval power in the western Mediterranean. In a series of bitter wars, Rome, too, developed a navy and defeated the Carthaginians. The Romans then turned their attention to Macedon and Greece. The chapter concludes with how and why Rome intervened in Greek affairs, and how the outcome of that intervention brought it an empire that encompassed the Mediterranean and transformed the society of Rome itself.