Demography of the Roman Empire
Demographically, the Roman Empire was an ordinary premodern state. It had a low life expectancy, high infant mortality, a low marriage age, and high fertility within marriage. At birth, Roman subjects had a life expectancy of about 20–25 years. Perhaps 15 to 35 per cent of Roman subjects died in childhood. Once Roman children survived to their fifth birthday, however, they could expect to live into their forties. Roman women could expect to bear on average 6 to 9 children.At its peak, before the Antonine Plague of the 160s CE, it had a population of about 60 million and a population density of about 16 persons per square kilometer. In contrast to the European societies of the classical and medieval periods, Rome had unusually high urbanization rates. During the 2nd century CE, the city of Rome had more than one million inhabitants. No Western city would have as many again until the 19th century.