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
Goryeo under Mongol Rule one of Kublai's daughters; later, a court lady from Korea called the Empress Gi became an empress through her marriage with Ukhaantu Khan, and her son, Biligtü Khan of the Northern Yuan dynasty, became a Mongol Khan. Furthermore, the kings of Goryeo held an important status within the Mongol imperial hierarchy, much like other important families of conquered or client states of the Mongol Empire (e.g. the Uyghurs, the (Oirats, and Khongirad). Some Mongolian sources claim that at least one Goryeo monarch who was raised at the Yuan court was the most beloved grandson of Kublai Khan. Militarily, following the