In 1809, Itsarasunthon succeeded his father Rama I, the founder of the Chakri dynasty, as Loetlanaphalai the King of Siam.

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.

Itsarasunthon with his concubine Riam (later elevated to Princess Mother Sri Sulalai by her own son), fathered Prince Tub (ทับ – later Rama III) in 1787.

In 1801, Rama I then found out that Princess Bunrod had been pregnant for four months and banished her out of the palace to live with her brother.

[3] As the eldest surviving legitimate son of Rama I, Prince Itsarasunthon succeeded to the throne when Buddha Yotfa Chulaloke died in 1809.

Loetlanaphalai's son, Prince Thap, effectively crushed the rebellion, proving himself to be competent, thus gaining his father's favor.

Prince Tub was raised to Kromma Muen, given the Sanskrit-derived name Chetsadabodin, and made Minister of Foreign Affairs.

[4] The Konbaung king Bodawpaya, seeing that Rama I was dead, marched an army into Chumphon and conquered Thalang (Phuket City) in the same year.

Loetlanaphalai sent his brother Maha Senanurak the Front Palace to recapture Thalang, which had been razed to the ground.

[5] It was said that during Rama II's reign, if one could write a refined piece of poetry, then one would be able to become a royal favorite, as Loetlanaphalai himself was a poet.

Since the Siamese revolution of 1688, Western presence had been reduced to a small scale as the Thai Kings ceased to encourage foreign influence.

[6] According to the succession rule then theoretically in force,[7] the throne would go to the son of Queen Sri Suriyendra, Prince Mongkut; however, his elder half-brother Chetsadabodin succeeded the same day.

Though only the son of a concubine, he had served their father in putting down a revolt and then as Kromma Tha (Ministry of Trade and Foreign Relations.)