Phutthayotfa Chulalok (born Thongduang; 20 March 1737 – 7 September 1809), posthumously honoured as King Phutthayotfa Chulalok the Great, also known by his regnal name Rama I, was the founder of the Rattanakosin Kingdom (now Thailand) and the first King of Siam from the reigning Chakri dynasty. He ascended the throne in 1782, following the deposition of King Taksin of Thonburi. He was also celebrated as the founder of Rattanakosin (now Bangkok) as the new capital of the reunited kingdom.
Rama I, whose given name was Thongduang, was born from a Mon male line descent family, great-grandson of Kosa Pan. His father served in the royal court of the Ayutthaya Kingdom. Thongduang and his younger brother Bunma served King Taksin in wars against the Burmese Konbaung dynasty and helped him in the reunification of Siam. During this time he emerged as Siam's most powerful military leader. Thongduang was the first Somdet Chao Phraya, the highest rank the nobility could attain, equaled to that of royalty. In 1782, he took control of Siam and crowned himself as the monarch. The most famous event in his reign was the Burmese–Siamese War (1785–1786), which was the last major Burmese assault on Siam.
