Shweli River (; ) is a river in China and Myanmar (Burma). Also known as Nam Mao (; ) in Shan or Dai, and Ruili River or Longchuan River (龙川江) in Chinese, it forms 26 km of the boundary between Burma and China. It is one of the tributaries of the Myanmar's chief river, the Ayeyarwady, and arises in Yunnan Province of China. It flows through northern Shan state and Sagaing Division, and enters the Ayeyarwady at Inywa, north of Tagaung and south of Katha. History Dai people, known as Shan in Burma, migrated from Yunnan into Burma along the Shweli. Maw Shans from Mong Mao settled in the Shweli valley, and raided and invaded the Bamar heartlands down the Shweli, some people believe that King Anawrahta of Bagan (1044–1077) reduced Mong Mao to a vassal state. But the event is that when the Anawrahta visited Nanzhao in quest of the Buddha's tooth while returning, married Sao-Môn-la, a daughter of the Mong Mao king. But there is nothing to show that the Mong Mao king ever had to acknowledge the overlordship of the Pagan monarch. The fall of the kingdom of Bagan in the 13th century, however, saw a resurgence of Shan power, although King Bayinnaung (1551–1581) of the Taungoo Dynasty succeeded in pacifying them to establish Burmese suzerainty once and for all. King Hsinbyushin (1763–1776) of the Konbaung Dynasty also successfully resisted Chinese army in Sino-Burmese War (1765-9) that advanced down the Shweli and Myitnge river valleys. The territory south of the Shweli, about , north of Namtu and from Namkham to the west, was under the control of the Communist Party of Burma (CPB) from 1968 to 1986. The Kachin Independence Army (KIA) controlled the area north of the Shweli, and the Shan State Army (SSA) and the Palaung State Liberation Army (PSLA) farther south. The Shweli river valley and the hills around Momeik (Mong Mit) and Mogok with its ruby mines had been old CPB strongholds since the 1950s. Momeik itself was captured by the Communists in 1977. The Burmese Army recaptured the territory in early 1987, and subsequently opened up border trade with China. Population The region is inhabited mainly by Shan people, some Kachin and Palaung and a few Chinese. Flora and fauna There are extensive marshes on both banks of the Shweli at the confluence with the Ayeyarwady. Hills are covered with broad-leaved species