Mongol Empire What is referred to in English as the Mongol Empire was called the "Ikh Mongol Uls" ("ikh": "great", "uls": "state"; Great Mongolian State). In the 1240s, one of Genghis's descendants, Güyük Khan, wrote a letter to Pope Innocent IV which used the preamble "Dalai (great/oceanic) Khagan of the great Mongolian state (ulus)". After the succession war between Kublai Khan and his brother Ariq Böke, Ariq limited Kublai's power to the eastern part of the empire. Kublai officially issued an imperial edict on 18 December 1271 to name the country Great Yuan ("Dai Yuan", or "Dai Ön Ulus") to establish the
Mongol invasions of Tibet in the late 1240s Mongolian prince Godan invited Sakya lama Sakya Pandita, who urged other leading Tibetan figures to submit to Mongol authority. This is generally considered to have marked the beginning of Mongol rule over Tibet, as well as the establishment of patron and priest relationship between Mongols and Tibetans. These relations were continued by Kublai Khan, who founded the Mongol Yuan dynasty and granted authority over whole Tibet to Drogon Chogyal Phagpa, nephew of Sakya Pandita. The Sakya-Mongol administrative system and Yuan administrative rule over the region lasted until the mid-14th century, when the Yuan dynasty began to