Ishad was an Old Turkic word used to designate the highest-ranking Göktürk generals (e.g., Buri-sad). It is also used in some Arabic sources to describe the Khagan Bek of the Khazars. Brook, citing Golden, proposes that Ishad is a variant of Shad, a Turkic title of Iranian origin.
Notes
References Kevin Alan Brook. The Jews of Khazaria. 3rd ed. Rowman & Littlefield Publishers, 2018. Douglas M. Dunlop. The History of the Jewish Khazars, Princeton, N.J.: Princeton University Press, 1954. Peter B. Golden. Khazar Studies: An Historio-Philological Inquiry into the Origins of the Khazars. Budapest: Akadémiai Kiadó, 1980. Norman Golb and Omeljan Pritsak, Khazarian Hebrew Documents of the Tenth Century. Ithaca: Cornell University Press, 1982.