This book studies the growth of the city of Rome and the effects of the city's demands for food and migrants on the economy of Italy. It seeks to question the idea that all great cities, especially in the ancient world, were parasites on the societies that supported them. On the contrary, the growth of Rome promoted development in agriculture, marketing systems and urbanization in Italy. The book reappraises not only the traditional view of Rome as a consumer city but also the history of Italy in the late Republic and early Principate.