This book is a comprehensive study of trade in Byzantium from the ninth to the twelfth century. It is divided in four sections which cover different aspects of the topic. The first one focus on geography examining the markets of Constantinople and the provinces respectively. Constantinople emerges as a special case not only because of the volume of commercial transactions taking place there, but also because of specific regulations concerning trade which were in vigour inside the zone of the capital. The second section addresses a rather debatable subject: the role of the byzantine state in trade. The state intervened in trade by imposing taxation and regulating the commercialisation of certain articles to which it attached particular importance. However, the author argues that trade in Byzantium was much less controlled than it is usually believed. The role of human factor, the merchant, is examined of the third section. Retail or wholesale merchants travelling often outside the borders of the Empire animated an extensively monetised economy. Foreign merchants took active part in byzantine trade, not necessarily as competitors of native merchants. Questions relative to permanent and temporary markets, as well as the infrastructures of trade are examined in the last section of the book.