Thailand, meaning "land of the free", was commonly known as Siam prior to 1949. One reason for the name change was because Thailand is famous as being the only Southeast Asian state to avoid European colonial rule, having acted as a buffer state between French Indochina and the British Empire. It is the world's 51st largest country and the 21st most populous.

Thailand is in the centre of the Indochinese peninsula and shares a border with Burma, Laos, Cambodia, and Malaysia. The country, along with neighbouring Cambodia, has the world's greatest concentration of Buddhists, with over 95% of the population adhering to the religion.

Before the arrival of the Portuguese in South-East Asia, modern-day Thailand was a part of the Ayutthaya Kingdom (1351–1767) which dominated the region. The capital, Ayutthaya, was situated an hour's drive north of Bangkok, and was one of a number of cities given the moniker "the Venice of the East". By 1700, it is estimated that Ayutthaya's population exceeded one million people, which would have made it the world's biggest city at the time.

After the Ayutthaya Kingdom fell to invading Burmese armies, the Rattanak Kingdom saw a period of relative stability for the area, which would last for 150 years until the revolution of 1932. Since then, Thailand has experienced fluctuating fortunes, with times of rapid economic growth interspersed between political upheaval and uncertainty.