Gurkhan
Gurkhan was a Mongol title meaning "Universal Ruler" and roughly equivalent to the older word khagan. It was held by the rulers of the Kara-Khitai in the 13th century. The title was first recorderd in the history after Yelü Dashi founded Kara-Khitan Khanate. It comes from the Middle Mongolian Gür / Kür, meaning "wide" or "general". Christopher I. Beckwith claims that the title has the meaning "the ruler of the earth" in his book Empires of Silk Road.