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 Vietnam third invasions occurred during the reign of Kublai Khan of the Yuan Dynasty. By this point, the Mongolian Empire had fractured into 4 separate entities with Yuan Dynasty being the strongest and biggest empire. These invasions resulted in a disastrous land defeat for the Mongols in 1285 and the annihilation of the Mongol navy in 1288. However, both the Trần dynasty and Champa decided to accept the nominal supremacy of the Yuan dynasty and serve as tributary states in order to avoid further conflicts. By the 1250s, the Mongol Empire controlled large amounts of Eurasia including much of Eastern Europe,