December 10 marks the Constitution Day which is held annually to commemorate the advent of the regime of Constitutional Monarchy in Thailand.

Previously, the government of Thailand was an absolute monarchy until June 24, 1932 there was a transition to constitutional monarchy led by a group of young intellectuals educated abroad and inspired by the concept of western democratic procedures. The group which was known as "People's Party or Khana Rasdr" was led by Luang Pradit Manudharm (Pridi Panomyong). To avoid bloodshed, King Rama VII graciously agreed to abolish absolute monarchy and handed over the country's first "Permanent" Constitution. In fact, King Rama VII (King Prajadhipok) had prepared, even before being asked, to hand over his powers to the people.

All Thai constitutions, however, recognise the King as Head of State, Head of the Armed Forces, Upholder of All Religions and sacred and inviolable in his person. His Majesty the King's sovereign power emanates from the people and is exercised in three ways, namely: legislative power through the National Assembly, executive power through the Cabinet and Judicial power through the law courts.

Even though the Revolution of 1932 brought an end to the centuries old absolute monarchy, the reverence of the Thai people towards their kings has not been diminished by this change.

Portraits of Thai kings are prominently displayed throughout the kingdom. On Constitution Day, the entire nation is greeted with festivity. The government offices, private buildings and most highrises are decorated with national flags and bunting and are brightly illuminated. On this day, all Thai citizens jointly express their gratitude to the king who graciously granted them an opportunity to take part in governing the country.