Until Kubla Khan conquered the kingdom of Nanchao, and many of its people fled to the south, this was the homeland of the Tai people. Today large numbers of ethnic Tais - known as Dai, Bai and other names - still inhabit many of the mountainous regions and plains, though two-thirds of Yunnan's 41 million population are now Han Chinese.
However, Yunnan is one of the most ethnically diverse provinces in Asia. The Bai and Dai are among the few registered ethnic minority groups to have populations over the one million mark. Yi, Naxi and Hani ethnic groups have also surpassed this mark. The Miao, Lisu, Hui, Lahu, Wa, Yao, Jingpo and Tibetan minorities all have populations exceeding 100,000, while the Bulang, Buyi, Pumi, A'chang, Nu, Jino, De'ang and Mongolian groups each exceed 10,000. The Shui, Manchu and Dulong have more than 4,000 members each.
Over the past 20 years, the government has recognised the importance of having a multi-ethnic nation, known as duominzu guojia. Writing systems are being developed for all minority languages in China, and elementary school students in some minority areas have been offered a choice of either Chinese or their minority language as the medium of instruction.
Although the country's official language is Mandarin, the Han speak a dialect of it, and almost all of the minority nationalities have their own languages.
Ethnic diversity in Yunnan has led to a varied and complex order of religious beliefs, which co-exist happily.
The four distinct religions are Buddhism, Taoism, Islam and Christianity, however one group may believe in several religions simultaneously, whilst other groups may share one common belief.
Taoism, introduced in the 7th century, is principally a Han belief, while Islam came to Yunnan around 1253 with the establishment of the Yuan Dynasty and the arrival of outside officials to replace local authorities.
An English missionary introduced Christianity in 1877.
Visitors to religious buildings are expected to dress neatly and conservatively, while treating religious figures or edifices with due respect - climbing on them is not considered respectful. Any rules on photography or filming should be followed strictly.
Men and women, irrespective of age or seniority, greet each other with a handshake. However, the Chinese are not physically demonstrative and, though a good friend may clasp both hands of the other as a gesture of affection, hugging, backslapping, open displays of affection or flirting are usually frowned upon.
The Chinese have high regard for older people, and will show courtesy and visible acknowledgment of the presence of an older person. Chinese surnames precede given names, and it is not considered polite to address people by their given name.
Two Chinese customs which may disconcert the foreign visitor are the slurping of food and prolonged staring. The former is a recognised sign of enjoyment, while the latter is not intended as rude or intrusive, merely curious.