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 invasion of the Latin Empire his erstwhile enemies, the Seljuks, at a critical juncture in 1242 while they were under Mongol attack. As a result, the position of Vatatzes was strengthened with regards to the rump Seljuk state and the position of Baldwin, defeated by the Mongols himself, was weakened. Mongol invasion of the Latin Empire In the summer of 1242, a Mongol army invaded the Latin Empire of Constantinople. The army, a detachment of the army under Qadan then devastating Bulgaria, entered the empire from the north. It was met by the Emperor Baldwin II, who was victorious in a first encounter but was