He was permitted to take with him the Phra Bang, a gold Buddharupa that had, according to legend had been originally brought from Angkor by Fa Ngum, the first king of Lan Xang, and was taken to Thonburi in 1779.

In 1791, Nanthasan convinced Rama I that King Anourouth of Luang Phrabang was secretly meeting with the Bamar-ruled Konbaung Kingdom and plotting a rebellion against Thonburi.

Two years later, Nanthasan was himself accused of plotting a rebellion with the Lao governor of Nakhon Phanom, allegedly having made diplomatic overtures to Tây Sơn Vietnam.

The temple was a major statement of his authority, since it was oriented so that when Anouvong's vassals came to pledge their annual allegiance, they physically turned their backs on Bangkok.

The potential crisis had caused the military to be on high alert, and the British Empire, who had recently begun the First Anglo-Burmese War, monitored closely the situation.

In the midst of these events, the Lao kings of Luang Phrabang, Vientiane, and Champasak made their way to Bangkok for the royal funeral ceremonies to be held the following year in accordance with custom.

Anouvong's retinue and one of his sons were impressed into corvee projects, including digging canals, felling sugar palms, harvesting bamboo, and constructing the Phra Samut Chedi.

His strategy involved three key points: 1) respond to the immediate crisis caused by the popular discontent over the forced tattooing; 2) remove the ethnic Lao on the Khorat Plateau to the Kingdom of Vientiane, conducting a scorched Earth policy as he did so to slow the inevitable Siamese pursuit; and 3) seek a diplomatic victory by gaining support from Vietnam, China or Britain.

From at least 1822, Siam had been purchasing large quantities of modern firearms and ammunition from Britain, which had a military surplus from the recently ended Napoleonic Wars.

Lao commanders also delayed to search for the Thai officials responsible for tattooing, forcing those captured to march north as prisoners.

Siam quickly organized a massive counterstrike and dispatched two armies, one by way of Saraburi to retake Nakhon Ratchasima, and the other through the Pasak Valley towards Lomsak.

Anouvong's forces withdrew to Nong Bua Lamphu, the strongest fortress on the Khorat Plateau and traditionally held by the crown prince of Vientiane.

Following the sacking of Vientiane, the rulers of Chiang Mai, Lampang, Lamphun, Nan, Phrae, and the kingdom of Luang Phrabang all pledged their renewed allegiance to Siam, although Phraya Bodindecha noted that they had “waited to see the turn of events, and their actions greatly depended on the outcome of the war.” Bodindecha spent several months organizing the removal of the remaining people from around Vientiane and confiscating all arms and ammunition.

The now furious Rama III ordered Chao Phraya Bodindecha to return and completely destroy Vientiane, and to capture Anouvong at all costs.

The remaining Lao kingdoms of Champasak and Luang Phrabang understandably came under stricter control and arms limitations, while the Khorat Plateau was formally annexed by Siam.

Regional rivals Siam and Vietnam would come into increasing conflict over control of the inland trade and Lao territory, leading to the Siamese-Vietnamese Wars of the 1830s.

Vietnam annexed the Lao principality of Xieng Khouang, and Chinese bandits after the Taiping rebellion were able to force their way down the Mekong River to fight what became known as the Haw Wars of the 1860s.

He has been credited with the existence of the modern country of Laos, which might have otherwise have been completely incorporated into Thailand, as was the neighboring Tai Yuan kingdom of Lanna.

In 2010, to coincide with the 450th Anniversary celebrations of Vientiane, the Laos government created Chao Anouvong Park, complete with a large bronze statue of the locally revered ruler.