[7] Ong Boun also offered[3] to send his daughter Princess Nang Kaeo Nhotfa Kanlayani[2] to be a consort of King Taksin.

Taksin replied in a letter in February 1776 that he would send an entourage to escort[3] the Lao princess to Thonburi next year but these marriage arrangements were not realized.

King Taksin then ordered[9] Chaophraya Chakri to bring armies to Nakhon Ratchasima and captured Phraya Nangrong.

Phra Vo also sent his son Thau Kam[2] to Nakhon Ratchasima to pledge alliance to Thonburi court and requested Siamese support.

Phra Vo's son Thau Kam survived and informed Nakhon Ratchasima that his father had been killed by the Vientiane forces.

He ordered Chakri and Surasi to lead the Siamese armies of 20,000[3] men from Thonburi to Nakhon Ratchasima to invade Vientiane in December 1778.

[8] This Siamese Invasion of Vientiane, however, did not serve merely as to avenge for Phra Vo's death but as to strengthen Siam by moving against a Burmese ally and to acquire new vassal kingdoms.

Ang Non then ordered Cambodian men to be gathered and levied from Kampong Svay, Srey Santhor, Preyveng and Tboung Khmum.

From Oudong, Chaophraya Surasi and his Cambodian army embarked on a riverine fleet and moved north upstream along the Mekong, passing the town of Sambour.

Phaya Supho, the Vientiane general who had earlier defeated Phra Vo, led the Lao defenses against the Siamese.

Chakri and Surasi combined their forces to attack the Lao towns of Pakho and Viengkhuk (in modern Mueang Nong Khai district).

Chakri pressed on to attack the town of Phanphrao (in modern Si Chiang Mai district), which situated on the Mekong just opposite of Vientiane.

Taksin ordered the Buddhist hierophant or Sangharaja and the whole monastic bureaucracy to receive the two sacred Buddha images at Saraburi, where they were put on a barge and proceeded.

King Taksin himself and his royal riverine entourage traveled from Thonburi to fetch the holy images at Bang Thorani (modern Tha Sai, Nonthaburi).

King Ong Boun, who had taken refuge in Khamkeut, managed to raise an army to stage a coup to return to power in Vientiane in 1781, killing Phaya Supho in the process.

The Siamese conquest of Laos in 1779 was immortalized by the installation of the Phra Kaew Buddha image at the spiritual center of Thai kingdom.

[1] After Chaophraya Surasi had left Cambodia to invade Vientiane, the pro-Siamese King Ang Non assigned his royal official to levy rice grain rations from local Cambodian peasants in Kampong Thom to be sent as food supplies to the Siamese armies.

King Ang Non punished those officials who were responsible for the works including Oknha Decho Thein the governor of Kampong Svay.

Tolaha Mu requested military supports from Nguyễn Phúc Ánh,[16] the Nguyen Lord who had been in Saigon fighting the Tây Sơn.

Ang Non marched his royal armies from Oudong to battle the Vietnamese at Kampong Chhnang but Đỗ Thanh Nhơn prevailed.

[1][7] Years of warfare and plunder during the Burmese Wars led to the plummet of population of Siam post-1767 and the manpower was in great need for the Siamese kingdom.

The rest of the captured Lao were distributed to other towns in Central Siam including Phetchaburi, Ratchaburi, Nakhon Chaisi and Prachinburi.

Lao royalties: the princes Nanthasen, Inthavong, Anouvong, Princess Kaeo Nhotfa or Khiawkhom[1] and other members were settled in Bang Yikhan[1] under the protection of the Siamese monarch.

[1] Lao commoners worked in the estates of the Siamese nobility[17] and became important labor workforce in the Early Rattanakosin Period.

Lao commoners in Bangkok were eventually settled in Bang Saikai (modern Hirun Ruchi, Thonburi District).

Emperor Quang Trung Nguyễn Huệ of the Tây Sơn sent armies to invade Luang Phrabang two times in 1790 and 1791[20][21] during the Lao–Vietnamese War (1790–1791).

King Nanthasen fought the Tây Sơn at Muang Phuan, securing victory and reported to the Siamese court.

[22] In 1791, Nanthasen of Vientiane reported to the Bangkok court that Anurutha of Luang Phrabang betrayed Siam by reaching agreements with either Burma[22] or Tây Sơn.

Nanthasen then sent secret messages to Queen Thaenkham,[3] the widow of Surinyavong who had been in political conflicts with Anurutha,[7] promising her the rulership of Luang Phrabang.

At the end of the reign of King Rama I, Sisaket, Ubon Ratchathani, Yasothon, Roi-et, Kalasin and Khonkaen[3] had existed as chiefdoms.