This work presents a new interpretation of early Islamic history in the light of a detailed scrutiny of the sources available. This interpretation not only uses newly discovered material but also, and perhaps to a greater extent, re-examines and re-interprets material which has been known to us for many decades. Indeed, the latter proved most rewarding in my study The ‘Abbāsid Revolution, and in this volume I follow basically the same approach, applying it to the whole Arab empire instead of only to the province of Khurāsān.

For the purposes of this work, a systematic attempt has been made to follow, as closely as possible, the establishment of an Islamic regime in Arabia and its sudden expansion into an empire. Special attention has been given to the way the Arab tribesmen were settled in the various provinces, their relationship with the conquered peoples, their varying interests, activities and rivalries, their relations with the central government and the attempts of the latter to establish its authority over the vast conquered territories. At the same time, an effort has been made to spare the reader the elaborate details of each particular situation and to present instead a concerted analysis of the constantly changing conditions all over the empire.

The events of this period have too often been explained on the basis of imaginary tribal jealousies or irrational personal conflicts.