This book aims to reinterpret, and in many places to discover for the first time, what the main lines of economic development were in the central medieval Mediterranean between the mid-tenth century and the end of the twelfth. This is not well understood; we are reliant on sketchy syntheses of fifty years ago. New work on archaeology, especially on ceramics, allows us to understand exchange much better than we could in the last century. The book discusses and compares the regional economies of Egypt, Tunisia, Sicily, the Byzantine Empire, Islamic Spain and Portugal, and north-central Italy. In each case, regional development was more important than the impulse of Mediterranean trade in itself, which developed, by contrast, essentially as a spin-off of regional developments. Egyptian shipping dominated the Mediterranean before 1100; Italian ships became increasingly important in the twelfth century. But Egypt remained the strongest Mediterranean economy, and Islamic Spain the fastest-growing economy, for the whole period of the book; out of the regions studied, northern Italy was the slowest to get off the ground. One of the main drivers in every case was the prosperity and thus demand of at least some strata of the peasant majority; another was the local force of the state. This overturns all previous assumptions about the period.
