Abū Saʿīd b. ʿAbd al-Ḥayy b. al-Ḍaḥḥāk b. Maḥmūd Gardīzī (fl. first half of the fifth/eleventh century) is important as an historian of the eastern Islamic world, in particular, for the first four centuries or so of Islam. His life and career are very obscure, with neither his birth nor death dates known. His family presumably came from Gardīz and the region of Zamīndāwar in eastern Afghanistan. He probably held some function at the Ghaznavid court or in the bureaucracy; the title of his book, the Zayn