What was the nation of Thailand known as prior to 1949?

Thailand, officially the Kingdom of Thailand and formerly known as Siam, is a country at the center of the Indochinese peninsula in Southeast Asia. With a total area of approximately 513,000 km2 (198,000 sq mi), Thailand is the world's 50th-largest country. It is the 20th-most-populous country in the world, with around 66 million people.

There is evidence of human habitation in Thailand that has been dated at 40,000 years before the present. Similar to other regions in Southeast Asia, Thailand was heavily influenced by the culture and religions of India, starting with the Kingdom of Funan around the 1st century CE to the Khmer Empire. Thailand in its earliest days was under the rule of the Khmer Empire, which had strong Hindu roots, and the influence among Thais remains even today.

In 1917, Siam joined the Allies of World War I and is counted as one of the victors of World War I. The bloodless revolution took place in 1932 carried out by the Khana Ratsadon group of military and civilian officials resulted in a transition of power, when King Prajadhipok was forced to grant the people of Siam their first constitution, thereby ending centuries of absolute monarchy. In 1939, the name of the kingdom, "Siam", was changed to "Thailand". The politics of Thailand is currently conducted within the framework of a constitutional monarchy, whereby the Prime Minister is the head of government and a hereditary monarch is head of state.