Genghis Khan controlled a significant territory.
Genghis Khan . He decreed the adoption of the Uyghur script as the Mongol Empire 's writing system . The Mongol Empire ( Mongolian : Mongolyn Ezent Güren ; Mongolian Cyrillic : Монголын эзэнт гүрэн ; [ mɔŋɡ ɮˈiːŋ ɛt͡sˈɛnt ˈɡurəŋ ] also Орда ( `` Horde '' ) in Russian chronicles ) existed during the 13th and 14th centuries and was the largest contiguous land empire in history .