The Thai-Lao conflict has a long history.

At the time of Siam's retributive campaigns against Vientiane in 1827-28, relations between Vientiane and Annam had been good.

The Vietnamese call Vientiane Van Tuong (the Kingdom of Ten Thousand Elephants), but when Vientiane's ruler, Chao Anou, seeks refuge in Hue following Siam's destruction of his capital, it causes serious embarrassment to the Vietnamese.

King Rama III of Siam writes to the Vietnamese emperor, Minh Mang, explaining that Chao Anou had refused obedience to him and had started hostilities.

Minh Mang, pursuing a consistently cautious policy toward Rama III, lends Chao Anou two companies of men to escort him back to Vientiane, instructing them to return immediately after accomplishing their mission.

Siamese and Vietnamese sources—the Laotian primary sources having for the most part disappeared—give conflicting versions of what happened next.

In any event, in mid-October 1828, Chao Anou finds himself once again engaged in hostilities with a stronger Siamese force. He again flees to safety, this time to Muang Phuan because a Siamese force is encamped at Nakhon Phanom, blocking the Mekong downstream.