Short answers, pulled from the story.
Rama I, born Thongduang on the 20th of March 1737, was the founder of the Rattanakosin Kingdom and the first king of Siam from the Chakri dynasty, which continues to rule Thailand today. He reunified Siam after the catastrophic fall of Ayutthaya in 1767 and established Bangkok as the new capital in 1782.
Rama I crowned himself on the 6th of April 1782, following the deposition of King Taksin of Thonburi. He is posthumously honored as King Phutthayotfa Chulalok the Great, and the Thai cabinet formally awarded him the epithet Maharat in 1982, 200 years after his accession.
Rama I relocated the capital to the east bank of the Chao Phraya river primarily for its better strategic location and to make a clean political break from Taksin's reign. He named the new capital Rattanakosin, meaning Keeping place of the Emerald Buddha, and installed the Emerald Buddha at Wat Phra Si Rattana Satsadaram.
The Nine Armies War, formally known as the Burmese-Siamese War of 1785-1786, was the last major Burmese assault on Siam, launched by King Bodawpaya. Siamese forces successfully defended including at Thalang (Phuket), where Chan and her sister Mook organized local resistance; Rama I honored them with the titles Thao Thep Kasattri and Thao Sri Sunthon.
In 1788, Rama I convened a council to review and standardize the Buddhist canon (Tipitaka). In 1805, his court compiled surviving legal texts into the Three Seals Law, named for the official seals authenticating its volumes, which remained central to Siam's legal system into the modern era.
Rama I died in Bangkok on the 7th of September 1809, aged 72, after a short but acute illness. According to Wat Pho's official history, he died at the Paisal Thaksin Throne Hall in the Grand Palace, and some of his ashes were later enshrined in the ordination hall of Wat Pho.