Here's an entry in the Ming historical annals that supposedly refers to the Hani tribal people of Yunnan:
"12 Nov 1433: In Yun-nan, the Niu-wu Chief's Office was established. Niu-wu, Wu-long and other stockades lay in He-ni territory. At this time, their chiefs Ren-zhe and Tuo-bi came to Court to offer tribute. When they came to the capital, they memorialized that their land was distant, where there were many yi people and fan. They requested that offices be established and officials appointed to govern the people. The Auxiliary Ministry of War requested that Wu-long be merged with Niu-wu and that a Niu-wu Chief's Office be established. This was approved. Subsequently Ren-zhe was appointed as Chief and Tuo-bi and others were appointed as deputies."
There is further information on Geoff Wade's polities page:
"89. Niu-wu ( 鈕兀 ): A polity noted by the MSL in only one reference of 1433 as a "Chief's Office" in Yun-nan. It was created by merging stockades in the territory of Ha-ni people (Xuan-zong shi-lu, juan 106.7b), and was located between Che-li (q.v.) and Yuan-jing (q.v.). See Tan Qi-xiang (1982; 77) and Fang Guo-yu (1987; 884, 893, 1072."
It's number 89 on this map. Near the three way intersection of the Vietnamese northern border with the Laotian border. This map has the current distribution of Hani populations in Yunnan.
Anyone who has lived in Chiangrai or Maesai, Thailand has met some Akha tribal people. Across the border from Maesai in Kengtung, Burma (Chiangtung, Chaing-dong) in the Eastern Shan states there is an even larger population that became Catholic early in this century.The Chinese branch of the Akha are called the Hani. Obviously there is a lot of history here waiting to be uncovered.