Phra Bat Somdet Phra Borommarajabongjet Mahesvarasundorn Phra Buddha Loetla Nabhalai, or Rama II (24 February 1767 – 21 July 1824), is the second monarch of Siam under the House of Chakri, ruling from 1809-1824.

In 1809, Isarasundhorn succeeds his father Buddha Yodfa Chulaloke, the founder of Chakri dynasty, as Buddha Loetla Nabhalai the King of Siam.

His reign is largely peaceful, devoid of major conflicts.

His reign is known as the "Golden Age of Rattanakosin Literature" as Buddha Loetla Nabhalai is patron to a number of poets in his court and the King himself is a renowned poet and artist.

The most notable poet in his employ is the illustrious Sunthorn Phu, the author of Phra Aphai Mani.