Nayan (Mongol Prince) 'Prince of Kwang-ning'. In addition, Nayan was also the foremost leader of the Eastern "ulus"es (tribal groupings and districts ruled by Mongol appanage princes) dominated by the descendants of the brothers of Genghis Khan. Whatever the precise extent of Nayan's appanage, he certainly held sufficient lands within and around Manchuria to give him a power-base from which to launch a rebellion against his kinsman Kublai Khan. Nayan is represented as embodying a traditional Mongol reaction against the increasing sinicisation shown by Kublai Khan and his administration. Nayan adhered to the ancestral nomadic values of the Mongols and was dismayed at
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,