Kingdom of Vientiane
By the 1720s Muang Phuan was supporting the Kingdom of Luang Prabang in wars against the Burmese, and Siamese. Under Chao Kham Sattha again Muang Phuan went to war against the Governor of Thakhek, a tributary to the Kingdom of Vientiane. In 1751 Chao Ong Lo went so far as to directly attack the Kingdom of Vientiane and was totally defeated, retreating to Houa Phan (today Sam Neua) where he began to raise another army. The Kingdom of Vientiane named Chao Ong Lo's brother Ong Bun as regional governor of Muang Phuan. The armies of Muang Phuan split between the brothers in civil war, and ultimately Chao Ong Lo prevailed. However the conflict drained the region so much so that for the next 37 years Muang Phuan remained a tributary to Vientiane.