Main article: Burmese–Siamese War (1785–86)
Bodawpaya of Burma pursued his ambitious campaigns to expand his dominions. The Burmese-Siamese War (1785–1786) was called “Nine Armies War” by Siam because the Burmese came in nine armies. The armies surged into Lan na and Northern Siam, yet the governor of Lampang managed to partly halt the Burmese, waiting for the troops from Bangkok. As Phitsanulok was captured, Rama I himself led an army to the north.
In the south, Bodawpaya was waiting at Three Pagodas Pass. The Front Palace led his troops to the south the counter-attacked the Burmese came from Ranong through Nakhon Si Thammarat and the engagements occurred at Kanchanaburi. The Burmese also attacked Thalang (Phuket), where to governor had just died. Chan, wife of the governor, and her sister Mook gathered people to defend Thalang against the Burmese. Today,[when?] Chan and Mook are revered as two heroines opposing the Burmese invasions.
The Burmese proceeded to capture Songkhla. Upon hearing the news, the governors of Phatthalung fled. However, a monk named Phra Maha encouraged the citizens to turn up their arms against the Burmese. Phra Maha was later raised to nobility by Rama I.
As his armies were destroyed, Bodawpaya retreated, only to renew attacks the next year (1786). Bodawpaya, this time, didn’t divide his troops but instead formed into single army. Bodawpaya passed through the Chedi Sam Ong and settled in Ta Din Dang. The Front Palace marched the Siamese forces to face Bodawpaya. The fighting was very short and Bodawpaya was quickly defeated. This short war was called “Ta Din Dang campaign”.