A group of military officers and civilians engineered a bloodless coup in Siam, ending the absolute rule of the Chakri dynasty.

The Siamese revolution of 1932 or Siamese coup d'état of 1932 was a coup d'état by the People's Party which occurred in Siam on 24 June 1932. It ended Siam's centuries-long absolute monarchy rule under the Chakri dynasty and resulted in a bloodless transition of Siam into a constitutional monarchy, the introduction of democracy and the first constitution, and the creation of the National Assembly. Dissatisfaction caused by the economic crisis, the lack of a competent government, and the rise of Western-educated commoners fueled the revolution.

Absolute monarchy is a form of monarchy in which the sovereign is the sole source of political power, unconstrained by constitutions, legislatures or other checks on their authority.

The Chakri dynasty is the current reigning dynasty of the Kingdom of Thailand. The head of the house is the king, who is head of state. The family has ruled Thailand since the founding of the Rattanakosin era and the city of Bangkok in 1782; following the end of Taksin's reign, when the capital of Siam shifted to Bangkok. The royal house was founded by Rama I, an Ayutthaya military leader of Sino-Mon descent.