Two unified Thai kingdoms emerged in the mid-13th century. The Sukhothai Kingdom, located in the south-central plains, gained its independence from the Khmer Empire to the east. By the late 13th century, Sukhothai’s territory extended into present-day Burma and Laos. Sukhothai lasted until the mid-15th century. The Thai Lan Na Kingdom was established in the north with its capital at Chang Mai; the Burmese conquered Lan Na in the 16th century. The Ayutthaya Kingdom (14th-18th centuries) succeeded the Sukhothai and would become known as the Siamese Kingdom. During the Ayutthaya period, the Thai/Siamese peoples consolidated their hold on what is present-day central and north-central Thailand. Following a military defeat at the hands of the Burmese in 1767, the Siamese Kingdom rose to new heights under the military ruler TAKSIN, who defeated the Burmese occupiers and expanded the kingdom’s territory into modern-day northern Thailand (formerly the Lan Na Kingdom), Cambodia, Laos, and the Malay Peninsula. The kingdom fought off additional Burmese invasions and raids in the late 1700s and early 1800s. In the mid-1800s, Western pressure led to Siam signing trade treaties that reduced the country’s sovereignty and independence. In the 1890s and 1900s, the British and French forced the kingdom to cede Cambodian, Laotian, and Malay territories that had been under Siamese control.

A bloodless revolution in 1932 led to the establishment of a constitutional monarchy. After the Japanese invaded Thailand in 1941, the government split into a pro-Japan faction and a pro-Allied faction backed by the king. Thailand became a US treaty ally in 1954 after sending troops to Korea and later fighting alongside the US in Vietnam. Thailand since 2005 has experienced several rounds of political turmoil, including a military coup in 2006 that ousted then Prime Minister THAKSIN Chinnawat and large-scale street protests led by competing political factions in 2008, 2009, and 2010. In 2011, THAKSIN's youngest sister, YINGLAK Chinnawat, led the Puea Thai Party to an electoral win and assumed control of the government.

In 2014, after months of major anti-government protests in Bangkok, the Constitutional Court removed YINGLAK from office, and the Royal Thai Army, led by Gen. PRAYUT Chan-ocha, then staged a coup against the caretaker government. The military-affiliated National Council for Peace and Order (NCPO) ruled the country under PRAYUT for more than four years, drafting a new constitution that allowed the military to appoint the entire 250-member Senate and required a joint meeting of the House and Senate to select the prime minister -- which effectively gave the military a veto on the selection. King PHUMIPHON Adunyadet passed away in 2016 after 70 years on the throne; his only son, WACHIRALONGKON (aka King RAMA X), formally ascended the throne in 2019. The same year, a long-delayed election allowed PRAYUT to continue his premiership, although the results were disputed and widely viewed as skewed in favor of the party aligned with the military. The country again experienced major anti-government protests in 2020. The reformist Move Forward Party won the most seats in the 2023 election but was unable to form a government, and Srettha THRAVISIN from the Pheu Thai Party replaced PRAYUT as prime minister after forming a coalition of moderate and conservative parties.

Geo-Informatics and Space Technology Development Agency (GISTDA; created in 2000 from the Thailand Remote Sensing Center that was established in 1979; GISTDA is under the Ministry of Higher Education, Science, Research and Innovation); National Space Policy Committee (NSPC; advisory body to the prime minister) (2024)

Has an ambitious and growing space program focused on the acquisition and operation of satellites and the development of related technologies; operates communications and remote sensing (RS) satellites; manufactures scientific/research/testing cube satellites and developing the capabilities to produce RS satellites (has historically built satellites with foreign assistance); cooperates with a range of foreign space agencies and industries, including those of other ASEAN countries, China, France, India, the Netherlands, Pakistan, Russia, South Korea, and the US; founding member of the China-led Asia-Pacific Space Cooperation Organization (APSCO); has a growing space industry, including Southeast Asia’s first dedicated satellite manufacturing facility, which opened in 2021 (2024)