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 supported Kublai's rival claimant, Ariqboke. Hulagu died on February 8, 1264. Berke sought to take advantage and invade Hulagu's realm, but he died along the way, and a few months later, Alghu Khan of the Chagatai Khanate died as well. Kublai named Hulagu's son Abaqa as a new Ilkhan, and Abaqa sought foreign alliances, such as attempting to form a Franco-Mongol alliance with the Europeans against the Egyptian Mamluks. Kublai nominated Batu's grandson Möngke Temür to lead the Golden Horde. Ariqboqe surrendered to Kublai at Shangdu on August 21, 1264. The establishment of the Yuan dynasty (1271–1368) by Kublai Khan