Early history of the Shan states is clouded in myth. Most states claimed having been founded upon a predecessor state with a Sanskrit name Shen/Sen. Tai Yai chronicles usually begin with the story of two brothers, Khun Lung and Khun Lai, who descended from heaven in the 6th century and landed in Hsenwi, where the local population hailed them as kings.^[30] The Shan, ethnic Tai peoples, have inhabited the Shan Hills and other parts of northern modern-day Burma as far back as the 10th century CE. The Shan kingdom of Mong Mao (Muang Mao) existed in Yunnan as early as the 10th century CE but became a Burmese vassal state during the reign of King Anawrahta of Pagan (1044–1077).^[31]

The first major Shan State of that era was founded in 1215 at Mogaung, followed by Mone in 1223. These were part of the larger Tai migration that founded the Ahom Kingdom in 1229 and the Sukhothai Kingdom in 1253.^[32] The Shans, including a new migration that came down with the Mongols, quickly came to dominate an area from northern Chin State and northwestern Sagaing Region to the present-day Shan Hills. The newly founded Shan States were multi-ethnic states that included a substantial number of other ethnic minorities like the Chin, Palaung, Pa-O, Kachin, Akha, Lahu, Wa and Burmans. The most powerful Shan states were Mohnyin (Mong Yang) and Mogaung (Mong Kawng) in present-day Kachin State, followed by Theinni (Hsenwi), Thibaw (Hsipaw), Momeik (Mong Mit) and Kyaingtong (Keng Tung) in present-day northern Shan State.^[33]