Nanzhao, also spelled Nanchao or Nan Chao, was a polity that flourished in what is now southern China and Southeast Asia during the 8th and 9th centuries. It was centered on present-day Yunnan in China.

Nanzhao comprised many ethnic and linguistic groups. Some historians believe that the majority of the population were of the Bai people, but that the elite spoke a variant of Nuosu (also called Yi), a Tibeto-Burman language closely related to Burmese.

Originally, there were several tribes that settled on the fertile land around the alpine fault lake Erhai. These tribes were called Mengshe (蒙舍), Mengsui (蒙嶲), Langqiong (浪穹), Dengtan (邆賧), Shilang (施浪), and Yuexi (越析). Each tribe had its own kingdom, known as a zhao in an area under the control of the Tibetan Empire. In the year 737 AD, with the support of the Tang Dynasty of China, Piluoge (皮羅閣) united the six zhaos in succession, establishing a new kingdom called Nanzhao (Mandarin, "Southern Zhao"). The capital was established in 738 at Taihe, (the site of modern-day Taihe village, a few miles south of Dali). Located in the heart of the Erhai valley, the site was ideal: it could be easily defended against attack and it was in the midst of rich farmland.

In 748, Piluoge was succeeded as king by his son Geluofeng (閣羅鳳). When the Chinese prefect of Yunnan attempted to rob Nanzhao envoys in 750, Geluofeng attacked, killing the prefect and seizing nearby Tang territory. In retaliation, the governor of the Tang province of Jiannan, Xianyu Zhongtong (鲜于仲通), attacked Nanzhao with an army of 80,000 soldiers in 751, but was defeated by General Duan Jianwei (段俭魏) with heavy losses (largely due to disease) at Xiaguan. Today the General's Cave (two kilometres west of Xiaguan), and the Tomb of Ten Thousand Soldiers (in Tianbao Park), bear witness to this disaster. Geluofeng then allied himself with the Tibetans. In 754, another Tang army of 100,000 soldiers, led by General Li Mi (李宓), approached the kingdom from the north, but it too was defeated with heavy losses.

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