Between 264 and 146 B.C., Rome fought three wars against its major rival in the Mediterranean, Carthage. Called the Punic Wars (because the Latin word for the Phoenicians, who settled Carthage, is Punicus), this conflict initially pitted a land power, Rome, against a sea power, Carthage. The most intense fighting took place in the Second Punic War (218-201 B.C.) when the Carthaginian general Hannibal nearly conquered all of Italy. Eventually, however, Hannibal was defeated by the Roman general Publius Cornelius Scipio, later surnamed Africanus for his conquest of Africa. When Roman armies destroyed the city of Carthage in 146 B.C. at the conclusion of the Third Punic War, the contest for control of the Mediterranean ended. Rome emerged from the Punic Wars as the major power in the region, and the defeat of Carthage set the stage for more conquests. The documents that follow trace the importance of the Punic Wars for Roman history, but also suggest reasons for the Roman triumph and the origins of Roman imperialism.

From 509 B.C. Rome was a republic in which power was shared by annually elected magistrates, a senate of distinguished citizens, and popular assemblies. The system gradually became more inclusive so that all citizens had a chance to participate at even the highest levels, yet at its core remained consensus among the aristocracy. But beginning with the turbulent career and murder of Tiberius Gracchus (133 B.C.), a series of crises shook the Roman political system to its very foundation, eventually destroying it. A new populist style of politics emerged in which senatorial consensus was bypassed and magisterial power subverted or abused. Violence became an ordinary tool of politicians, and civil war broke out as Roman fought Roman for supremacy. Julius Caesar was the most successful politician in this new style, and his assassination (44 B.C.) just after he had attained supremacy left the Republic leaderless and in turmoil. From the ensuing chaos one man, his adopted son Octavian, emerged supreme. Styled Augustus in 27 B.C., he was the first ruler of the new Roman government, the Principate, in which one man held all power.

Over two centuries ago, the historian Edward Gibbon described the Roman Empire of the second century A.D. as the "most happy and prosperous" period in human history. He regarded the period of the pax romana (Roman Peace) as the one in which any reasonable person would wish to have lived. It most certainly was a time of pleasure and prosperity for some: the entire Mediterranean region had been unified under one government, a feat never before or since accomplished, and millions lived in relative prosperity under a stable government far from the threat of war. But not all were happy: as the historian Tacitus, who lived during the pax Romana, wrote, "The Romans are a people who make a desert and call it peace." Injustice and oppression remained part of the order of the day, and the huge Roman armies did not long stand idle.