This book is a study of the pre-Islamic passages of Abu Hanifa Ahmad ibn Dawud ibn Wanand Dinawari's Kitab al-Akhbar al-Tiwal. It is intended for scholars of Late Antiquity. Special emphasis is placed on Dinawari's exposition of the rule of the Sasanian dynasty and questions relating to the mysterious Khudaynama tradition which are intimately connected with it. Beginning with a discussion of Dinawari and his work, the book moves into a discussion of indigenous Iranian historiography. Speculation on the sources of Kitab al-Akhbar al-Tiwal follows, and the historiographical investigation of the most substantial portion of Kitab al-Akhbar al-Tiwal's notices on the Sasanian dynasty comes next. The findings of the book are set out in a narrative of Sasanian history at the end. This book was written with one main question in mind: what does Dinawari's Kitab al-Akhbar al-Tiwal have to say about pre-Islamic Iranian history? A host of other questions arose immediately: who was Dinawari; when did he live; what did he do; how was his work perceived by others; where did Dinawari get his information and how did he present it; is Dinawari's information reliable?