Yunnan, though a province of China, is, in many aspects, a part of Southeast Asia. This is the case because it is populated not only by Han Chinese who have migrated into the province in more recent times but by a large number of minorities who have been living here for as long as history has been recorded. Actually, one of the dominant ethnic groups of Southeast Asia, the Thais, trace their origin to Yunnan where they lived in their own, independent kingdom, Nanchao, for hundreds of years, until it was overrun by the Mongols of Kublai Khan. Dschingis Khan's and Kublai Khan's conquest of much of Asia forced many of the Thais of Yunnan, mainly those living in an advanced social order, the Nanchao state, to migrate south into an area which today forms the Kingdom of Thailand.

Nevertheless, a large number of ethnic Thais remained in Yunnan after Kublai Khan's conquest, especially in the mountainous regions of Yunnan which have less easily been penetrated, first by Kublai Khan's troops and later by Han Chinese administrations. Though these remaining Thais, known as Dais, Bais, and by other names, have, after Nanchao, never again been able to form their own, independent states, they have, until today, maintained their own way of life, their own religion, and their own customs which in many ways are quite different from those of the Han Chinese.
 

Yunnan is probably the most colourful, and the most diverse Chinese province. The particular ethnic mix certainly contributes to this fact.

Actually, Yunnan is among the ethnically most diverse regions not only of China but of all of Asia, comparable in diversity to its neighbor in the South and East, the Union of Myanmar (Burma).