In 1779, under the reign of King Setthathirath II of Lan Xang, Kitsarat, an heir of Sourigna Vongsa, declared separation of Luang Prabang.

The Siamese army helped defend Vientiane but could not stop Kitsarat to form his own kingdom.

King Ong Bun contacted the Konbaung dynasty for help, turning Vientiane into a Burmese vassal.

In 1791, Nanthasen convinced King Rama I that Luang Prabang was secretly plotting a rebellion against Siam.

In 1795, Nanthasen was accused of plotting a rebellion with the Lao governor of Nakhon Phanom.

He took Nakhon Ratchasima in January but the Siamese quickly organized a massive counterattack.

The city was burned to the ground and was looted of nearly all treasures, its population completely relocated.

The vacuum of power allowed the French, now already controlled Cambodia and Cochinchina, to push north to the Mekong River, with hope of establishing a waterway to China.