Constitution Day is observed in Thailand every December 10 to celebrate the anniversary of the adoption of the first Constitution of Thailand in 1932. This public holiday commemorates the bloodless revolution led by a group of military and civilians, known as the People's Party, which ended the absolute monarchy in Siam. They drafted a provisional constitution that limited King Prajadhipok's power, paving the way for the establishment of a constitutional monarchy. The constitution, promulgated on December 10, 1932, declared that sovereign power belonged to the people, while the king would exercise royal power with the advice of the People's Assembly, the State Council, and the Courts. On this day, people in Thailand enjoy free festive events and concerts, taking the opportunity to celebrate their democratic heritage.