Rattanakosin Kingdom (1782–1932) in the context of "Thonburi Kingdom"

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.

Battambang (Khmer: បាត់ដំបង, UNGEGN: Bătdâmbâng [ɓatɗɑmɓɑːŋ]) is the capital of Battambang province and the third largest city in Cambodia. The city is situated on the Sangkae River, which winds its way through the province.

Battambang was founded in the 11th century by the Khmer Empire. It later became a major commercial hub and the capital of the Siamese province of Inner Cambodia. It was reintegrated into Cambodia during French colonisation. During the 20th century, Battambang was Cambodia's second largest city, but it was overtaken by the growth of Siem Reap. It was impacted by conflict and genocide in the 20th century, with the city forcibly evacuated during the Democratic Kampuchea period. It was also the site of fighting during the Khmer Rouge insurgency until the 1990s.

The Kingdom of Luang Phrabang, also called Kingdom of Luang Prabang was formed in 1707 as a result of the split of the Kingdom of Lan Xang. When the kingdom split, Muang Phuan became a tributary state of Luang Prabang. Over the years the monarchy weakened even more, and was forced to become a vassal various times to the Burmese and the Siamese monarchies.

A French consulate was established in the capital of Luang Prabang in 1885. The kingdom was at this time a Siamese vassal, who feared French plans of annexing of Luang Prabang. A treaty was signed on 7 May 1886 between Siam and France recognizing Siamese suzerainty over Luang Prabang and neighboring Lao kingdoms. France conducted expeditions in the region, searching for the possibility of establishing French territory there. A particularly destructive attack during the Haw wars by the Chinese Black Flag Army in 1887 saw King Oun Kham request French protection. This was accepted and signed on 27 March 1889, against Siamese protest.

Norodom (Khmer: ព្រះនរោត្តម, Nôroŭttâm [nɔˈroːɗɑm]; born Ang Voddey (Khmer: អង្គវតី, Ângk Vôtei [ʔɑŋ ʋɔˈtəj]); 3 February 1834 – 24 April 1904) was King of Cambodia from 19 October 1860 until his death in 1904. He was the eldest son of King Ang Duong and was a half-brother of Si Votha and King Sisowath. He was elected to the throne in 1860 but would not be crowned until 1864 because Siam held the royal regalia (the royal crown and other artifacts).

In 1863, he signed a treaty with France by giving France control over Cambodia's foreign relations in exchange for personal protection against his enemies. The treaty saved Cambodian independence, but French control over Cambodia's internal affairs strengthened continually until the end of his reign (full independence was not restored until 1953). His reign of 43 years and 188 days is the longest in Cambodian history in terms of verifiable exact date. Upon his death, he was succeeded by his half-brother, Sisowath.

The Kingdom of Siam, now known as Thailand, is one of the lesser known participants in World War I on the Allies side. Siam contributed to the fight against the Central Powers in one of the critical campaigns of the war. It sent an Expeditionary Force to France to serve on the Western Front.

At the start of the war in 1914, Siam declared their neutrality. The Kingdom maintained this status until July 1917 when it declared war on Germany and Austria-Hungary. Following both military and specialist training, a Siamese military contingent arrived on the Western Front in mid-September 1918, only two months before the war ended. Following the Armistice of 11 November 1918, Siamese troops contributed to the initial occupation of Rhineland, when they took over the town of Neustadt an der Haardt.

The Shan States were a collection of Shan (Tai) principalities called möng whose rulers bore the title saopha (sawbwa). The term "Shan States" was first used during the British rule in Burma as a geopolitical designation for certain autonomous areas of Burma, analogous to the princely states of British India. The terms "Siamese Shan States" and "Chinese Shan States" were also used to refer to the Tai principalities in northern Thailand and southern Yunnan, which instead came under the suzerainty of the Kingdom of Siam or Qing dynasty.

Historical mention of the Shan states inside the present-day boundaries of Burma began during the period of the Pagan dynasty; according to the Tai chronicles, the first major Shan State of that era was founded in 1215 at Möng Kawng, followed by Möng Nai in 1223. These were part of the larger Tai migration that founded the Ahom Kingdom in 1229 and the Sukhothai Kingdom in 1253. Shan political power increased after the Mongols overran Pagan in 1287 and the Shans came to dominate many of the northern to eastern areas of Burma—from northwestern Sagaing Division to the present-day Shan Hills. The newly founded Shan States were multi-ethnic states that included a substantial number of other ethnic minorities such as the Chin, Palaung, Lisu, Pa-O, Kachin, Wa, and Burmans.