According to the tomb tablet of Cuan Longyan, they were descended from a famous official in Shanxi, however it was common at the time to create fictitious lineages linking indigenous elites back to China, and it's also highly likely that the Cuans were originally native to Yunnan.
The Northern Zhou dynasty granted him the title of prefectural governor (刺史) of Southern Ningzhou (南寧州).
In contemporary Chinese historical records, the polity was called "Xicuan guo" (Western Cuan State).
The eastern half of the Cuan kingdom comprised present-day north east Yunnan and much of contemporary Guizhou Province.
The area was dominated by a mixture of agriculturalists who controlled the fertile lowlands of western Guizhou and eastern Yunnan (the former Yelang and Luowo kingdoms) and of powerful patricians who raised horses and sheep in the remote highlands of northeast Yunnan and northwest Guizhou (the former Bi kingdom).
[5]In 618, the Tang dynasty assigned Duan Lun as Commander-in-Chief (zongguan) to Yizhou (Chengdu).
Duan sent his subordinate, Yu Dashi, into Hongda's territory to persuade local tribes to give their allegiance to the Tang.