His father, Phraya Ratchaburi, joined Taksin's forces to recapture the city. Under King Taksin, Chim's father rose rapidly to high rank as a military leader and was assigned with the campaigns to subjugate Laos and Cambodia. In 1782, his father crowned himself King of Siam (later named Rama I) and Chim himself was raised to the title of Prince Itsarasunthon of Siam.

Itsarasunthon with his concubine Riam