Towards the end of 1254 Uriang Kadai left his armies in the field, and returned to Mongolia to report to Mangu the work done in the south beyond China. Sent back the next year, he entered through Lower Tibet, and continued his conquests. The kingdom of Ava as well as two others, was either subjected or terrified into yielding. Two years later, in 1257, the Mongol general appeared on the edge of Tung king (Gan nan) and summoned its sovereign, Chen chi kung, a vassal of the Sung Emperor, to own himself tributary to Mangu. Since his envoys did not return to him the general entered Gan nan and marched to the Tha River, which runs through the whole kingdom lengthwise. On the opposite bank he saw the enemy’s army with an immense force of elephants in order of battle. The Mongols, disposed in three parts, crossed and routed the enemy. The king hurried into a boat, sailed with the current and fled to an island; a part of his army escaped in boats also. Uriang Kadai ordered Che she tu to lead a division to the other bank of the river, but not to give battle till the rest of the army had crossed over. Che she tu was to seize all the boats, or take a stand between them and the enemy. Instead of obeying he put the enemy to flight before the other divisions could cross and prevented thereby the capture of the army. Uriang Kadai in his rage gave a biting reproof and threatened a trial, whereupon Che she tu immediately took poison and died. Kiao chi, the Gan nan capital, surrendered, and now Uriang Kadai found his envoys in prison. They had been bound with bamboo cords so firmly that the bonds had entered their flesh, and one of the men died the same hour in which he was liberated. Uriang Kadai was so enraged at this spectacle, that he gave up the city to be sacked by his warriors. After his troops had taken nine days of rest, he turned northward for a time to escape the great heat of the region. In 1258 the Gan nan king, Chen chi kung, resigned in favor of his eldest son, Chen kuang ping. The latter now sent his son-in-law and many great lords on an embassy to Mangu, who at that time was marching against the Sung empire. In 1256 Mangu had assembled a Kurultai at a place called Orbolgetu. During two months he treated the princes of his house with magnificence. All other guests summoned thither he met in the same way, and gave them rich presents. At this time came the submission of Corea, which, since 1247, had ceased to pay tribute. The success of Mongol arms in that country forced the king to render homage in person.