Langkasuka. Kanduli centred on what is now Surat Thani Province and Langasuka in Pattani Province. Southern Thailand was the centre of Hinduism and Mahayana Buddhism. The Tang monk Yijing stopped at Langkasuka to study Pali grammar and Mahayana during his journey to India around 800. At that time, the kingdoms of Southern Thailand quickly fell under the influences of the Malay kingdom of Srivijaya from Sumatra. Tamil King Rajendra Chola I, The Great, of the Chola dynasty invaded the Tambralinga Kingdom in southern Thailand in the 11th century. Northern Thailand According to the Cāmadevivaṃsa, the city of Hariphunchai (modern Lamphun) was founded by hermits. Camadevi, a princess of the Lavo Kingdom, was invited to rule the city around 700. However, this date is considered too early for the foundation of Hariphunchai as Camadevi brought no dharmachakras to the north. Hariphunchai may be a later (10th century) offshoot of the Lavo Kingdom or instead related to the Thaton Kingdom. Hariphunchai was the centre of Theravada in the north. The kingdom flourished during the reign of King Attayawong who built Wat Phra That Hariphunchai in 1108. The kingdom had strong relations with the Mon Kingdom of Thaton. During the 11th century, Hariphunchai waged lengthy wars with the Tai Ngoenyang Kingdom of Chiang Saen. Weakened by Tai invasions, Hariphunchai eventually fell in 1293 to Mangrai, king of Lan Na, the successor state of the Ngoenyang Kingdom. Arrival of the Tais The most recent and accurate theory about the origin of the Tai people stipulates that Guangxi in China is really the Tai motherland instead of Yunnan. A large number of Tai people known as the Zhuang still live in Guangxi today. Around 700 AD, Tai people who did not come under Chinese influence settled in what is now Điện Biên Phủ in modern Vietnam according to the Khun Borom legend. Based on layers of Chinese loanwords in proto-Southwestern Tai and other historical evidence, Pittayawat Pittayaporn (2014) proposed that this migration must have taken place sometime between the eighth–10th centuries. Tai speaking tribes migrated southwestward along the rivers and over the lower passes into Southeast Asia, perhaps prompted by the Chinese expansion and suppression. Chinese historical texts record that, in 722, 400,000 'Lao' rose in revolt behind a leader who declared himself the king of Nanyue in Guangdong. After the 722 revolt, some 60,000 were beheaded. In 726, after the suppression of a rebellion