The Siamese Revolution of 1932 or the Siamese Coup d'état of 1932 (Thai: การปฏิวัติสยาม พ.ศ. 2475 or การเปลี่ยนแปลงการปกครองสยาม พ.ศ. 2475) was a crucial turning point in Thai history in the 20th century. The revolution or the coup d'état was a bloodless transition on 24 June 1932, in which the system of government in Siam was changed from an absolute monarchy to a constitutional monarchy. The revolution was brought about by a group of military and civilians, who formed Siam's first political party, Khana Ratsadon (Peoples' Party). The revolution ended 150 years of absolutism under the House of Chakri and almost 700 years of absolute rule of Kings over Thai history. The Revolution was a product of global historical change as well as social and political changes domestically. The revolution also resulted in the people of Siam being granted their first Constitution.