The expansion and stabilization of the empire created great wealth, much of which flowed into Rome. The city, with a population of over a million, may have been the largest city in the world at that time. Fire and crime were perennial problems even in Augustus’s day, and sanitation was poor. In the second century urban planning and new construction greatly improved the situation. For example, engineers built an elaborate system that collected sewage from public baths, the ground floors of buildings, and public latrines. They also built hundreds of miles of aqueducts, most of them underground, to bring fresh water into the city from the surrounding hills.

Rome grew so large that it became ever more difficult to feed its residents. Emperors solved the problem by providing citizens with free oil, wine, and grain for bread. By doing so, they also stayed in favor with the people. They and other sponsors also entertained the people with gladiatorial contests in which participants fought using swords and other weapons. Some gladiators were criminals or prisoners of war, but by the imperial period increasing numbers were volunteers, often poor immigrants who saw gladiatorial combat as a way to support themselves. All gladiators were trained in gladiatorial schools and were legally slaves, although they could keep their winnings and a few became quite wealthy. The Romans were even more addicted to chariot racing than to gladiatorial shows. Winning charioteers were idolized just as sports stars are today.