Arabic-speakers can claim the Prophet Muhammad as one of their own, but Iranians have bragging rights when it comes to turning a desert religion into a world civilization, and this is the point emphatically made in the present volume, built about a conference at the University of California at Los Angeles honoring Ehsan Yarshater. Yarshater himself takes the lead, providing an essay that fills nearly half the book, in which he shows that “the Persian presence among the Arabs goes back to pre-Islamic times,” thereby having an influence on the culture in which Islam initially appeared and which was subsequently carried around the world with the Islamic religion. Further, Yarshater and his colleagues show how Iranian ways profoundly influenced both Islam itself (such as the notions of Messianic deliverance, the five daily prayers, and the practice of ritual purity) and then the nascent Muslim society. For example, in the realm of government, the seclusion of rulers, the wearing of luxurious clothing, the institution of the qadi (religious judge), and the diwan (governmental department) all go back to Iranian precedents. Other areas of influence include architecture, coinage, pharmacology, military technique, music, and secretarial practices. In all, Yarshater finds that the first phase of Islamic civilization was Arabic, the second Persian. Other authors in the volume look in depth at such matters as astronomy, poetry, mysticism, painting, and the writing of history. Of special interest is a final chapter, by Gerhard Doerfer, on the vast Persian linguistic and literary influence among the Turks. In all, this volume establishes that Iran and its culture have had a deep, pervasive, and abiding influence on Islam, and through it reached such disparate regions as eastern Europe and India.