gave Chinese titles to the brothers as subordinates of Kyawswa. The brothers resented the new arrangement as it directly reduced their power. On 17 December 1297, the three brothers overthrew Kyawswa, and founded the Myinsaing Kingdom. The dethronement forced the Mongol government to intervene again, leading to the second Mongol invasion of Burma (1300–01). The invasion failed. Two years later, on 4 April 1303, the Mongols abolished the province of Zhengmian (Cheng-Mien), evacuated Tagaung, and returned to Yunnan. Legacy The war was one of several near simultaneous wars waged by the Mongol Empire in the late 13th century. Though it was never more than a minor frontier war to the Mongols, the war set off a series of enduring developments in Burma. The invasions ushered in a period of political fragmentation, and the rise of Tai-Shan states throughout mainland Southeast Asia. Age of political fragmentation The immediate result of the war was the collapse of the Pagan Empire. However, the war merely accelerated the collapse but did not cause it. Pagan's disintegration was "in fact more prolonged and agonized." The kingdom had been in long gradual decline since the early 13th century. Had Pagan possessed a stronger central government, the collapse could have been temporary, and the country “could have risen again”. But the dynasty could not recover, and because the Mongols refused to fill the power vacuum, no viable center emerged in the immediate aftermath. As a result, several minor states fought it out for supremacy for the better part of the 14th century. It was only in the late 14th century that two relatively strong powers emerged in the Irrawaddy basin, restoring some semblance of normalcy. The vast region surrounding the Irrawaddy valley would continue to be made up of several small Tai-Shan states well into the 16th century. Rise of Tai-Shan states Perhaps the most enduring legacy of the Mongol invasions was the emergence of Tai-Shan states in mainland Southeast Asia. The Tai-Shan people who came down with the Mongol invasions stayed. By the early 14th century, several Tai-Shan states had come to dominate a vast region from present-day Assam to northern and eastern Myanmar to northern and central Thailand and Laos. Their rise was encouraged by the Mongols, who viewed the states as a useful buffer between Yunnan and the rest of Southeast Asia. The Mongols, who were still trying to incorporate Yunnan into the central