Who they were
Born Thongduang at Ayutthaya in 1737, he rose to become a leading general under King Taksin, holding the title Chao Phraya Chakri. He took the throne in April 1782 after Taksin’s deposition, and is known posthumously as Phra Phutthayotfa Chulalok.
What they did
He moved the capital from Thonburi across the river to the east bank — Rattanakosin Island — founding Bangkok, and built the Grand Palace and Wat Phra Kaew, where the Emerald Buddha was installed in 1784. He restored Ayutthayan court forms and Buddhist institutions, by tradition convening a council to revise the Buddhist canon in 1788, and compiled the Three Seals Law Code (1805). A complete Thai Ramakien was produced in his reign, parts of it attributed to the king himself. His forces crushed Bodawpaya’s Nine Armies invasion of 1785–86.
Legacy
The dynasty he founded still reigns, through ten kings from Rama I to Rama X. April 6, the date of his accession, is Chakri Memorial Day, and Bangkok’s rise from garrison town to royal capital begins with him.