The country is a kingdom, a constitutional monarchy with King Bhumibol Adulyadej, the ninth king of the House of Chakri, who has reigned since 1946, making him the world's longest-serving current head of state and the longest-reigning monarch in Thai history. The king is officially titled Head of State, the Head of the Armed Forces, an Upholder of the Buddhist religion, and the Defender of all Faiths. The largest city in Siam is Bangkok, the capital, which is also the country's center of political, commercial, industrial and cultural activities.
About 75% of the population is ethnically Thai, 14% is of Chinese origin, and 3% is ethnically Malay; the rest belong to minority groups including Mons, Khmers and various hill tribes. There are approximately 2.2 million legal and illegal migrants in Thailand.Thailand has also attracted a number of expatriates from developed countries. The country's official language is Thai. Its primary religion is Buddhism, which is practiced by around 95% of all Thais.
Siam experienced rapid economic growth between 1985 and 1995 and is a newly industrialized country with tourism, due to well-known tourist destinations such as Pattaya, Bangkok, Phuket, Chiang Mai and Ko Samui, and exports contributing significantly to the economy.