A sweeping, revisionist history of the Roman Empire from one of our foremost classicists. Ancient Rome was an imposing city even by modern standards, a sprawling imperial metropolis of more than a million inhabitants, a "mixture of luxury and filth, liberty and exploitation, civic pride and murderous civil war" that served as the seat of power for an empire that spanned from Spain to Syria. Yet how did all this emerge from what was once an insignificant...