During the 19th to 20th centuries, Siam (now known as Thailand) implemented large-scale changes to Buddhism. For the purpose of this debate, the "Siamese reforms" include:
(1) The creation of a new order of monks, the Thammayut, which promoted strict, text-based Buddhism with royal backing,
(2) The centralization of all monks under a national hierarchy headed by appointees of the king,
(3) The requirement that all monks belong to an officially recognized temple, and allowing only state-approved monks to ordain new monks.
Siam was the only Southeast Asian country never formally colonized, despite widespread colonization of neighbouring countries.