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
Division of the Mongol Empire state of the Mongol army and engaged in an unusual passive truce with each other. In 1260, the Mamluks advanced from Egypt, being allowed to camp and resupply near the Christian stronghold of Acre, and engaged Kitbuqa's forces just north of Galilee, at the Battle of Ain Jalut. The Mongols were defeated, and Kitbuqa was executed. This pivotal battle marked the western limit for Mongol expansion, as the Mongols were never again able to make any serious military advances farther than Syria. In a separate part of the empire, another brother of Hulagu and Möngke, Kublai Khan, heard of the