Somdet Phra Bawornrajchao Maha Sura Singhanat was the younger brother of Rama I, the first monarch of the Chakri dynasty of Siam. As an Ayutthayan general, he fought alongside his brother in various campaigns against Burmese invaders and the local warlords. When his brother crowned himself as the king of Siam at Bangkok in 1781, he was appointed the Front Palace or Maha Uparaj, the title of the heir. During the reign of his brother, he was known for his important role in the campaigns against Bodawpaya of Burma.

Phra Bat Somdet Phra Phutthayotfa Chulalok Maharat, personal name Thongduang (ทองด้วง), also known as Rama I, was the founder of the Rattanakosin Kingdom and the first monarch of the reigning Chakri dynasty of Siam. His full title in Thai is Phra Bat Somdet Phra Paramoruracha Mahachakkriborommanat Phra Phutthayotfa Chulalok. He ascended the throne in 1782, following the deposition of King Taksin of Thonburi. He was also celebrated as the founder of Rattanakosin as the new capital of the reunited kingdom.