This book was first published in 1967, and has since held the field. It has been welcomed by Al-Azhar, the most authentic seat of Islamic learning and it has received wide and warm acclaim from leading scholars, both in the east and the west. One feels so humble at this recognition. Studies of the first century of Islam have remained confined mainly to the technical scholar. The general reader has not had access so far to the wealth of material on the subject. An attempt to draw a clear and an intragated picture of the complicated situation obtaining in the first century of Islam was by no means easy. The field was certainly difficult to handle, calling as it did for a great deal of patience, research and discerning scholarship.