Due to the fact that little is known of the history of Muang Sing prior to the late 18 th century we start this short excursion into the history of Muang Sing at the end of the 19 th century. In 1887, Muang Sing was established and more than 1000 subjects had to be moved to the new capital of the principality of Chiang Khaeng and the surrounding plain. The relocation of the capital from Muang Yu became necessary to be better protected against a Burmese punitive expedition.

In 1895/96, after Muang Sing had been in an insecure status because the British had conquered Asia in 1885/86, quarrels took place within the ruling family. Finally an armed intervention by Bangkok which was triggered by territorial claims took place. Cao Fa Sili No, the ruler of the principality finally recognized the sovereignty of Siam . Not later than 1890 Muang Sing was a tributary of Bangkok.

In 1895 British troops, coming from Birma, invaded Muang Sing. The ruler of the principality, Cao Fa Sili No fled to Luang Namtha, which was already controlled by the French. After failed negotiations between England and France about the status of the region as a buffer state, the region east of the Mekong fell under French influence (later the protectorate of Luang Prabang), the regions in the west came under British control. Therefore in 1895/96 Muang Sing came under French control.

French troops were permanently stationed. Near the southern corner of the town they erected a military fort, thereby destroying the ancient city wall in that sector. Moreover the colonial administration built an asphalt road from Muang Sing to the Chinese border. On the outer side of the ‘ China road' they built a market and behind that market a new brick wall. The ‘urban' population shifted gradually towards this road, the town's economic lifeline.

In 1916 the French officially removed the last ruler of Muang Sing, Cao Fa Mom Ong Kham, because he tried to seek independence from France with the support of Chinese armed groups who, in 1914, had invaded and made insecure large parts of northern Laos . The hitherto special status of Muang Sing as a protectorate was abolished and the district came under direct control of the colonial administration.

During the first decades under French rule Muang Sing expanded. Several monasteries were founded within the town wall.

In 1946 the Chinese Kuomintang attacked Muang Sing. Even though the market was completely destroyed, the importance of the ‘ China Road ' did not decline. The market was newly built in 1954 and was again attracting traders from far and near.

In 1954 the French had to leave the Kingdom of Laos . Today Muang Sing is part of the Lao People's Democratic Republic.