by a 'Lao' leader in the present-day Guangxi, over 30,000 rebels were captured and beheaded. In 756, another revolt attracted 200,000 followers and lasted four years. In the 860s, many local people in what is now North Vietnam sided with attackers from Nanchao, and in the aftermath, some 30,000 of them were beheaded. In the 1040s, a powerful matriarch-shamaness by the name of A Nong, her chiefly husband, and their son, Nong Zhigao, raised a revolt, took Nanning, besieged Guangzhou for fifty seven days, and slew the commanders of five Chinese armies sent against them before they were defeated, and many of their leaders were killed. As a result of these three bloody centuries, the Tai began to migrate southwestward. The Simhanavati legend tells us that a Tai chief named Simhanavati drove out the native Wa people and founded the city of Chiang Saen around 800 CE. For the first time, the Tai people made contact with the Theravadin Buddhist kingdoms of Southeast Asia. Through Hariphunchai, the Tais of Chiang Saen embraced Theravada Buddhism and Sanskrit royal names. Wat Phrathat Doi Tong, constructed around 850, signified the piety of Tai people on the Theravada Buddhism. Around 900, major wars were fought between Chiang Saen and Hariphunchai. Mon forces captured Chiang Saen and its king fled. In 937, Prince Prom the Great took Chiang Saen back from the Mon and inflicted severe defeats on Hariphunchai. Around 1000 CE, Chiang Saen was destroyed by an earthquake with many inhabitants killed. A council was established to govern the kingdom for a while, and then a local Wa man known as Lavachakkaraj was elected king of the new city of Chiang Saen or Ngoenyang. The Lavachakkaraj dynasty would rule over the region for about 500 years. Overpopulation might have encouraged the Tais to seek their fortune further southwards. By 1100 CE, the Tai had established themselves as Po Khuns (ruling fathers) at Nan, Phrae, Songkwae, Sawankhalok, and Chakangrao on the upper Chao Phraya River. These southern Tai princes faced Khmer influence from the Lavo Kingdom. Some of them became subordinates to it. Sukhothai Kingdom (1238–1438) Thai city-states gradually became independent of the weakened Khmer Empire. It is said that Sukhothai Kingdom was established as a strong sovereign kingdom by Sri Indraditya in 1238 AC. A political feature which "classic" Thai historians call "father governs children" existed at this time. Everybody could bring their problems