The Nam Xan River joins the Mekong River at Pakxan on the border with Thailand, opposite Bueng Kan.[citation needed] Pakxan is connected to the south of Laos by Route 13.

These invasions began to reduce the populations of Xieng Khouang and Bolikhamsai, but it was the Siamese who completed the depopulation by deporting most of the Phou Eun inhabiting the region.

[2] In 1876, Rama V, King of Siam, ordered the creation of Bolikhamsai with the last survivors of the Haw invasion of 1874.

From 1885, the French, who took over neighboring Vietnam, challenged Siamese sovereignty over Laos.

After Auguste Pavie's mission dating the Mekong to Luang Prabang, the Siamese were forced to leave the left bank of the Mekong and evacuate the position they had created at the mouth of the Nam Xan River.