Thonburi Kingdom in the context of "Kingdom of Champasak"

Bangkok, officially known in Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies 1,568.7 square kilometres (605.7 sq mi) in the Chao Phraya River delta in central Thailand and has an estimated population of 11.4 million people as of 2024, 15.9% of the country's population. Over 17.4 million people (25% of Thailand's population) live within the surrounding Bangkok Metropolitan Region as of the 2021 estimate, making Bangkok a megacity and an extreme primate city, dwarfing Thailand's other urban centres in both size and importance to the national economy.

Bangkok traces its roots to a small trading post during the Ayutthaya era in the 15th century, which eventually grew and became the site of two capital cities, Thonburi in 1767 and Rattanakosin in 1782. Bangkok was at the heart of the modernization of Siam during the late 19th century, as the country faced pressures from the West. The city was at the centre of the country's political struggles throughout the 20th century, as Siam—later renamed Thailand—abolished absolute monarchy, adopted constitutional rule, and underwent numerous coups and several uprisings. The city, incorporated as a special administrative area under the Bangkok Metropolitan Administration in 1972, grew rapidly during the 1960s through the 1980s and now exerts a significant impact on Thailand's politics, economy, education, media, and modern society.

Thai Chinese (also known as Chinese Thais, Sino-Thais) are people of Chinese descent in Thailand. Thai Chinese are the largest mixed group in the country and the largest overseas Chinese community in the world with a population of approximately 9.5 million people, accounting for 11–14 percent of the country's total population as of 2012. It is also one of the oldest and most prominently integrated overseas Chinese communities, with a history dating back to the 1100s. Slightly more than half of the ethnic Chinese population in Thailand trace their ancestry to Chaoshan, proven by the prevalence of the Teochew dialect among the Chinese community in Thailand as well as other Chinese languages. The term as commonly understood signifies those whose ancestors immigrated to Thailand before 1949.

The Thai Chinese have been deeply ingrained into all elements of Thai society over the past 200 years. The present Thai royal family, the Chakri dynasty, was founded by King Rama I who himself was partly Chinese. His predecessor, King Taksin of the Thonburi Kingdom, was the son of a Chinese father from Chaoshan. With the successful integration of historic Chinese immigrant communities in Thailand, a significant number of Thai Chinese are the descendants of intermarriages between ethnic Chinese and native Thais. Many of these descendants have assimilated into Thai society and self-identify solely as Thai.

The Rattanakosin Kingdom, also known as the Kingdom of Siam after 1855, refers to the Siamese kingdom (in modern-day Thailand) between 1782 and 1932. It was founded in 1782 with the establishment of Rattanakosin (Bangkok), which replaced the city of Thonburi as the capital of Siam. This article covers the period until the Siamese revolution of 1932.

The kingdom governed based on the mandala system. This allows for high-autonomy locally with the kingdom influencing and effectively ruling its area of suzerainty. At its zenith in 1805 to 1812, the Kingdom was composed of 25 polities, ranging from duchies and principalities to federations and kingdoms. With the furthest extent reaching the Shan States, southern Yunnan, Laos, Cambodia, northern Si Rat Malai and Kawthoung. The kingdom was founded by Rama I of the Chakri dynasty. The first half of this period was characterized by the consolidation of Siamese power in the center of Mainland Southeast Asia and was punctuated by contests and wars for regional supremacy with rival powers Burma and Vietnam. The second period was one of engagements with the colonial powers of Britain and France in which Siam remained the only Southeast Asian state to maintain its independence.

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.

Thonburi (Thai: ธนบุรี) is an area of modern Bangkok. During the era of the Ayutthaya Kingdom, its location on the right (west) bank at the mouth of the Chao Phraya River had made it an important garrison town, which is reflected in its name: thon (ธน) a loanword from Pali dhána 'wealth', and buri (บุรี), from púra, 'fortress'. The full formal name was Thon Buri Si Mahasamut (กรุงธนบุรีศรีมหาสมุทร 'City of Treasures Gracing the Ocean'). For the informal name, see the history of Bangkok under Ayutthaya.

In 1767, after the sack of Ayutthaya by the Burmese armies, General Taksin took back Thonburi and, by right of conquest, made it the capital of the Thonburi Kingdom, crowning himself king until 6 April 1782, when he was deposed. Rama I, the newly enthroned king, moved the capital across the river, where stakes driven into the soil of Bangkok for the City Pillar at 06:45 on 21 April 1782 marked the official founding of the new capital. Thonburi remained an independent town and province, until it was merged with Bangkok in 1971. Thonburi stayed less developed than the other side of the river. Many of the traditional small waterways, khlongs, still exist there, while they are nearly gone from the other side of the river.

The Burmese–Siamese War (1775–1776) or Maha Thiha Thura's Invasion of Siam or Athi Wungyi's War (Thai: สงครามอะแซหวุ่นกี้) was a major military conflict between the Konbaung dynasty of Burma (now Myanmar) and the Thonburi Kingdom of Siam (now Thailand).

After the Mon Rebellion of 1774 and the successful Siamese capture of Burmese-held Chiang Mai in 1775, King Hsinbyushin assigned Maha Thiha Thura the general of Sino-Burmese War to conduct a large-scale invasion of Northern Siam in late 1775 in order to curb the rising Siamese power under King Taksin of Thonburi. As the Burmese forces outnumbered the Siamese, the three-month siege of Phitsanulok was the main battle of the war. Defenders of Phitsanulok, led by Chaophraya Chakri and Chaophraya Surasi, resisted the Burmese. The war reached stalemate until Maha Thiha Thura decided to disrupt the Siamese supply line, leading to the Fall of Phitsanulok in March 1776. The Burmese gained upper hand but the untimely demise of King Hsinbyushin ruined the Burmese operations as the new Burmese king ordered the withdrawal of all troops back to Ava. The premature exit of Maha Thiha Thura from war in 1776 left the remaining Burmese troops in Siam to retreat in disarray. King Taksin then took this opportunity to send his generals to harass the retreating Burmese. The Burmese forces had completely left Siam by September 1776 and the war was over.