Phutthaloetla Naphalai (born Chim; 24 February 1767 or 1768 – 21 July 1824), also known by his regnal name Rama II, was the second King of Siam from the Chakri dynasty, ruling from 1809 to 1824. In 1809, Itsarasunthon succeeded his father Rama I, the founder of the Chakri dynasty, as Loetlanaphalai the King of Siam. His reign was largely peaceful, devoid of major conflicts. His reign was known as the "Golden Age of Rattanakosin Literature" as Loetlanaphalai was patron to a number of poets in his court, and the King himself was a renowned poet and artist. The most notable poet in his employ was the illustrious Sunthorn Phu, the author of Phra Aphai Mani. The rapid growth of the number of his descendants was outstanding: he is believed to have had over 240 grandchildren.

Chim was born in 1767 during the Ayutthaya Kingdom in Amphawa District, Samut Songkram. He was a son of Luang Yokkrabat of Ratchaburi and Nak of Samut Sakorn, as his father and mother were then known. They would later become King Rama I and Queen Amarindra, respectively.

In 1767, Ayutthaya fell to Konbaung Burmese invaders. 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 (later elevated to Princess Mother Sri Sulalai by her own son), fathered Prince Thap (ทับ – later Rama III) in 1787. Prince Itsarasunthon then had a secret affair with his own cousin, Princess Bunrot. 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. Itsarasunthon, however begged his father to forgive him and the princess was reinstated and became his consort through the negotiation by concubine Khamwaen. Unfortunately, the baby died just after its birth. With Princess Bunrot, Itsarasunthon also fathered Mongkut (1804) and Pinklao (1808). His another concubine namely Prang Yai, gave birth to Prince Nuam in 1808.

He also married his agnatic half sister, Princess Kunthon Thipphayawadi. They had three sons: Prince Abhorn (1816), Prince Klang (1819), and Prince Piu (1822). Later, Prince Klang would be known as Prince Mahamala. He was granted the title of Krom Khun Bumraap Porapuksa, the 4th level of Krom ranks by Mongkut then elevated to Krom Phraya by Chulalongkorn.

Prince Itsarasunthon was appointed to the Front Palace as Lord of the Front Palace or Uparaja in 1807 to succeed his uncle Maha Sura Singhanat who had died in 1803, though he continued to stay at the Thonburi Palace. Among his many other children was Prince Wongsa Dhiraj Snid (born Prince Nuam), who was a royal physician for many years as well as a field commander and diplomat.

As the eldest surviving legitimate son of Rama I, Prince Itsarasunthon succeeded to the throne when Buddha Yotfa Chulaloke died in 1809. No royal naming system was established at the time Rama II was crowned. He was later named by his son Nangklao as Loetlasulalai but changed to Loetlanaphalai by his other son Mongkut and by the Rama convention, called Rama II. His consort, Princess Bunrod, was raised to Queen Sri Suriyendra.

As soon as Loetlanaphalai ascended the throne, Prince Kshatranichit, the surviving son of Taksin, rebelled as pretender to the throne. Loetlanaphalai's son, Prince Thap, effectively crushed the rebellion, proving himself to be competent, thus gaining his father's favor. Thap was raised to Kromma Muen, given the Sanskrit-derived name Chetsadabodin, and made Minister of Foreign Affairs.