Li Yong, Emperor of Nanming, retreated to the southwest, and some Han people moved to Yunnan and Upper Myanmar with Nanming Army. Since the early Qing Dynasty, the Han nationality in Kokang area has increased. One of them, Yang's family, moved to Kegan Mountain and became a local power, and followed the example of the local chieftain to rule the local ethnic minorities. 1840, Yang Guohua was officially named as a hereditary county magistrate by the Qing dynasty for his meritorious service in defending China's frontier defense, and became a chieftain regime of the Han people recognized by the central government, maintaining hereditary leadership for nearly 150 years. For a long time, the brave toaster Yang paid tribute to China and Mubang. 1886, the British Empire annexed the Pound Dynasty of Myanmar, and the chieftain of North Myanmar surrendered to Myanmar was also included in British India. Britain signed a treaty with China in the Qing Dynasty, which made it clear that there was no stable chieftain on the border between China and Myanmar. Some chiefs were divided into China and some belonged to British Burma. After years of negotiations, 1897 "Sino-British Treaty on the Continuation of Myanmar" was boldly included in the scope of British India.