According to an ancient chronicle, the original city of Chiang Saen was built in 545 CE in an area called Yonok, by Tai migrants from the Chinese province of Yunnan, and was an important city of the Lan Na Kingdom. No reliable written history of the city exists until the arrival of King Mengrai in the 13th century. The city was sacked by Chao Kawila of Chiang Mai during the reign of Rama I, because it had been the Burmese base of operations in the preceding years. The city was deserted, while its inhabitants resettled in other Bangkok-allied Lanna cities such as Lampang and Chiang Mai.