Siam The Haw Wars (Thai: สงครามปราบฮ่อ) were fought against Chinese quasi-military refugee gangs invading parts of Tonkin and the Laos from 1865–1890.

Liu Yongfu and Black forces fighting the French acquired a certain legitimacy and fame of the Vietnamese ruler Tự Đức.

[3] Further to the west, starting from about 1872, bands of defeated rebels began drifting across the frontier into Laos, then a tributary state of the Kingdom of Siam.

Responding to this serious challenge, in 1874 Chao Oun Kham, king of Luang Prabang, and the Nguyen monarch Tự Đức, sent a joint army to expel the invaders.

The victorious Haw moved south to sack Vientiane, while Chao Unkham sent urgent appeals for assistance to the Thai monarch, King Chulalongkorn (Rama V).

The expedition failed to achieve its primary objective, since the Haw refused to give battle and withdrew into the mountains of Phuan and Huaphan.

McCarthy was greatly impressed by the beauty and natural wealth of the regions, but found the inhabitants living a "wretched existence...harried, mutilated and slaughtered by robbers".

Hora (Thai: โหร, romanized: Hon) accompanying the Siamese troops, determined that 10 o'clock on the morning of 22 February 1885 was the most auspicious time to begin the assault.

The Thai and Laotian troops advanced in companies of 50 men, each under the White Elephant flag of Siam, and established themselves behind a temporary palisade 100 metres from the Haw fort.

McCarthy noted that most of the firing seemed to come from the Haw watchtowers and, despite Thai and Lao courage and almost reckless indifference to injury, "considerable execution" was caused to them.

At 14:00 the Thais suffered a further setback when their commander-in-chief, Phraya Raj, was injured by a shot "weighing about two pounds, which glanced off the post of a Chinese joss house where he was standing and struck him in the leg."

One memorial to the Thai and Lao soldiers killed in the struggle stands in front of the old Nong Khai City Hall, now a community center and museum.

Down by the Mekong River in view of Laos on the opposite side stands Wat Angkhan (อังคาร), which is from the Pali language for "ashes of the dead", and is also Thai for the planet Mars that Romans named for their God of War.