Tengri, or Gok Tengri, "blue sky", is attested across the historical record of the Turkic and Mongolic steppe peoples as the supreme sky god and ultimate source of cosmic order, recorded as early as the Orkhon inscriptions of the eighth century, the oldest surviving Turkic-language texts, which credit Tengri directly with granting the Turkic khagans their right to rule.
Unlike many sky gods elsewhere who preside over a crowded pantheon of equally significant peers, Tengri in the classical steppe conception stands closer to a single supreme, largely abstract cosmic principle, the sky itself understood as living and aware, with other spirits and lesser deities, including Umay and Yer-Sug, the earth-water spirits, occupying subordinate roles beneath this overarching sky. The khagan's title, "Tengri qut", roughly "the charisma or fortune granted by Tengri", made Tengri's favour the direct theological basis of Mongol and Turkic imperial legitimacy, most visibly under Genghis Khan, whose thirteenth-century Mongol Empire justified its conquests explicitly as a mandate granted by Tengri to unite "all the peoples living in felt tents" under a single rule.