Central Thailand in the context of "Isan"

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.

Southern Thailand (formerly Southern Siam and Tambralinga) is the southernmost cultural region of Thailand, separated from Central Thailand by the Kra Isthmus.

Mass migration of Tai peoples from China (Guangxi) to Mainland Southeast Asia and Northern Thailand occurred between the 8th-10th century. The Mainland region was ruled by the Khmer Empire since 800 CE. The Thai established their own kingdoms: the semi-legendary Singhanavati Kingdom (691 BCE–638 CE) evolved into the Ngoenyang Kingdom (638–1292). In 1220, the Khmer controlled Sukhothai was conquered by the Thais and made the capital of the Sukhothai Kingdom. By 1220, the long declining Khmer Empire was mostly overrun by Thais. By the 13th century, the Sukhothai Kingdom (1238–1438) had replaced the Mon kingdoms in Central Thailand. During the reign of King Ramkhamhaeng the Thai script was created in 1283, the arts flourished, Thai institutions were developed, and people called themselves "Thai" as freed people from foreign rule.

In 1351, the Suphannabhum city-state (modern-day Suphan Buri), and Lavo city-state (modern-day Lop Buri) merged into the Ayutthaya Kingdom which was founded near the Chao Phraya River. Duarte Fernandes was the first European to arrive in Ayutthaya in 1511. Siam became the popular international name for Thailand.

Thai people, historically known as Siamese people, are an ethnic group native to Thailand. In a narrower and ethnic sense, the Thais are also a Tai ethnic group dominant in Central and Southern Thailand (Siam proper). Part of the larger Tai ethno-linguistic group native to Southeast Asia as well as Southern China, Thais speak the Sukhothai languages (Central Thai and Southern Thai language), which is classified as part of the Kra–Dai family of languages. The majority of Thais are followers of Theravada Buddhism.

Government policies during the late 1930s and early 1940s resulted in the successful forced assimilation of various ethno-linguistic groups into the country's dominant Central Thai language and culture, leading to the term Thai people to come to refer to the population of Thailand overall. This includes other subgroups of the Tai ethno-linguistic group, such as the Northern Thais and the Isan people, as well as non-Southeast Asian and non-Tai groups, the largest of which is that of the Han Chinese, who form a substantial minority ethnic group in Thailand.

Northern Thailand the oldest region in Thailand the main ethnic group Tai-Lue established their own kingdoms: the semi-legendary Singhanavati Kingdom (691 BCE–638 CE) evolved into the Ngoenyang Kingdom (638–1292). In 1220, the Khmer controlled Sukhothai was conquered by the Thais and made the capital of the Sukhothai Kingdom. By 1220, the long declining Khmer Empire was mostly overrun by Thais. By the 13th century, the Sukhothai Kingdom (1238–1438) had replaced the Mon kingdoms in Central Thailand. During the reign of King Ramkhamhaeng the Thai script was created in 1283, the arts flourished, Thai institutions were developed, and people called themselves "Thai" as freed people from foreign rule.

In 1351, the Suphannabhum city-state (modern-day Suphan Buri), and Lavo city-state (modern-day Lop Buri) merged into the Ayutthaya Kingdom (Tai-Lue from the Northern+Monic from Chao Phra Ya river basin = Siamese Kingdom) which was founded near the Chao Phraya River. Duarte Fernandes was the first European to arrive in Ayutthaya in 1511.

Eastern Thailand is a region of Thailand, bordering Cambodia in the east, Northeastern Thailand in the north, and Central Thailand in the west.

Sukhothai Historical Park (Thai: อุทยานประวัติศาสตร์สุโขทัย (Pronunciation)) covers the ruins of Sukhothai, literally 'dawn of happiness', capital of the Sukhothai Kingdom in the 13th and 14th centuries, in north central Thailand. It is near the city of Sukhothai Thani, capital of Sukhothai province.

The city's walls form a rectangle about 2 km (1.2 mi) east-west by 1.6 km (0.99 mi) north-south. There are 193 ruins on 70 km (27 sq mi) of land. There is a gate in the centre of each wall. Inside are the remains of the royal palace and twenty-six temples, the largest being Wat Mahathat. The park is maintained by the Fine Arts Department of Thailand with help from UNESCO, which has declared it a World Heritage Site. Each year, the park welcomes thousands of visitors.