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 The transition of the capital of the Mongol Empire to Khanbaliq (Dadu, modern-day Beijing) by Kublai Khan in 1264 was opposed by many Mongols. Thus, Ariq Böke's struggle was for keeping the center of the Empire in Mongolia homeland. After Ariq Böke's death, the struggle was continued by Kaidu, a grandson of Ogedei Khan and lord Nayan. By eliminating the Song dynasty, Kublai Khan completed the conquest of China. The fleets of the Yuan dynasty attempted to invade Japan in 1274 and 1281, but both invasion failed, and a large number of their ships were destroyed in sea storms named