It was the prevailing religion of the Turks, Mongols, Bulgars, Xiongnu, Huns, and, possibly the Magyars, and the state religion of several medieval states: Göktürk Khaganate, Western Turkic Khaganate, Eastern Turkic Khaganate, Old Great Bulgaria, Danube Bulgaria, Volga Bulgaria, and Eastern Tourkia (Khazaria). In "Irk Bitig", a ninth century manuscript on divination, Tengri is mentioned as (God of Turks). According to many academics, Tengrism was a predominantly polytheistic religion based on shamanistic concept of animism, and during the imperial period, especially by the 12th–13th centuries, Tengrism was mostly monotheistic.