Thonburi Kingdom - Reunification and Expansion

Reunification and Expansion

There were still local warlords competing for Siam. Taksin marched first in 1768 to Pitsanulok to subjugate the Lord of Pitsanulok who ruled over Upper Chao Phraya Basin. Taksin was injured during the campaign and had to retreat. The war readily weakened Pitsanulok and then it was in turn subjugated by the Lord of Sakwangburi. The same year Taksin sent Thong Duang and Boonma to tame the Prince Theppipit – the ruler of Phimai to the north of Nakhon Ratchasima on the Khorat Plateau. The prince was a son of Borommakot and was defeated by Thonburi armies. Theppipit fled to Vientiene but was captured and then executed.

In 1769, Taksin sent Phraya Chakri south to subjugate the Lord of Nakorn Si Thammarat. The lord fled to Pattani but was returned to Taksin, who reinstalled him back as the ruler of Nakorn Si Thammarat under Taksin's governance.

Prince Ang Non the Uparaja of Cambodia fled to Thonburi in 1769 after his conflicts with King Narairaja for Siamese supports. Taksin then took this opportunity to request tributary from Cambodia, which Narairaja refused. Taksin sent Phraya Abhay Ronnarit and Phraya Anuchit Racha to subjugate Cambodia, taking Siemreap and Battambang. But Taksin's absence from the capital (in wars with Nakorn Si Thammarat) shook the political stability and the two generals decided to retreat to Thonburi.

By this time, the only rival to Thonburi authority was the Sakwangburi lordship led by the powerful monk Chao Phra Faang. Chao Phra Faang’s domain encompassed the northernmost territories bordering Lanna to Nakhon Sawan to the south as the result of annexation of Pitsanulok lordship in 1768. In 1770,Chao Phra Faang sent reinforcements southwards reaching Chainat. Taksin perceived this action as threats and decided to invade Sakwangburi beforehand. The royal fleet marched upstream the Chao Phraya River and took Pitsanulok with ease. Taksin then divided the armies into the east one led by Boonma and the west one led by Phraya Pichai to be joined at Sakwangburi. Sakwangburi quickly fell after three days and Chao Phra Faang went lost.

Taksin stayed at Pitsanulok to oversee the census and levy of northern population. He appointed Boonma to Chao Phraya Surasi as the governor of Pitsanulok and all northern cities and Phraya Abhay Ronnarit to Chao Phraya Chakri the chancellor.

Later in 1771, Taksin decided to finish off the Cambodian campaign by assigning Chao Phraya Chakri command of land forces with Prince Ang Non and Taksin himself went by fleet. The Siamese took various Cambodian cities and drove Narairaja out of the throne. Ang Non was installed as Reamraja and Narairaja became the Uparaja with the Cambodian court paying tribute to Thonburi.