This work is a continuation of my attempt to present a new interpretation of Islamic history. It deals with the three centuries between the rise of the ʿAbbāsids and the Saljūq invasion. This period witnessed the establishment of a new regime, its failure to live up to its revolutionary ideals and the gradual dissolution of a vast empire into lesser political entities. The ʿAbbāsids failed to establish a political structure supported by viable institutions to rule their domains. They also failed to take measures to accomplish the economic integration of their empire because they could not comprehend nor were they able to cope with the rapid expansion of trade. This problem was the more baffling to them for it demanded fundamental changes in the structure of the basically agricultural economy they had inherited to allow for an economic structure in which trade could be exploited to the advantage of all concerned. New taxation systems were required to divide the burden of taxes equitably between the prosperous inhabitants of the urban trade centres and the long-suffering agricultural communities. The entrenched vested interests in the cities took advantage of their political power to oppose such measures and the rural communities had no alternative but to revolt in the face of this continued injustice.

The impact of the vast increase in the volume of trade went far beyond the purely economic front, for it was not only internal trade that was involved but also an international trade of unprecedented dimensions.