Overview
Chatusadom or Catustambha ( , literally "Four Pillars" from Sanskrit Catur "Four" + Stambha "Pillars") was the Thai system of central executive governance during the Ayutthaya Kingdom, Thonburi Kingdom and Rattanakosin Kingdom from 1454 to 1892. For about four hundred years, it had served as the constitution of central government of Siam or Thailand until King Chulalongkorn organized Chatusadom into modern ministries and officially established the Cabinet on April 1, 1892.
The Chatusadom system
King Trailokanat promulgated the constitution of Chatusadom in his Palatine Law, or Phra aiyakan tamnaeng na phonlaruean (), with the promulgation date being 1454. The original written law had been lost, however. Chatusadom went through subsequent amendments over time and King Rama I enacted the Palatine Law in the Three Seals Law, from which the Chatusadom was mostly studied. The Chatusadom bureaucracy was divided into Phonlaruean () or Civil Affairs and Thahan () or Military Affairs. Chatusadom was led by two Prime Ministers, alternatively Grand Chancellors () who held the rank of Chaophraya. Below Samuhanayok in Civil affairs were the Four Ministries, from which Chatusadoms name was derived. Each ministry was led by a Senabodi or Minister who held the rank of Phraya and each ministry had a Thai and a Sanskrit-derived name.
These four ministers were collectively called Wiang-Wang-Khlang-Na (). The Senabodi ministers of the Four Ministries held the rank of Phraya in the Ayutthaya period. However, during the late Ayutthaya and Bangkok period the ranks of these ministers rose to Chaophraya. The yokkrabat () was an official of the palace administration appointed to reside in provincial towns and oversee legal affairs. It was a long-established official post of administrative importance. Yokkrabat acted as the king's representative in legal matters, supervising adjudication and reporting on the conduct of governors and officials. In some contexts, the office functioned similarly to the head of a provincial court and a deputy to the governor.
During the late nineteenth and early twentieth centuries, the traditional office was gradually replaced by a modern prosecution service, and in 1916 the title yokkrabat was formally abolished and replaced by public prosecutors under the Ministry of Justice.
History and subsequent amendments
The Four Ministries of Chatusadom or Wiang-Wang-Khlang-Na had existed in Ayutthaya before 1455. Each ministry was called Krom and the ministers held the rank of Khun. The chancellor of the executives in Early Ayutthaya was called Senabodi ( from Sanskrit Senapati) who oversaw the Ministries. King Trailokanat organized and institutionalized the Four Ministries into bureaucratic apparatus in the Palatine Law of 1454. The seals of top three ministers were stamped on the Three Seals Law. King Rama I who was formerly Chaophraya Chakkri the Samuha Nayok established the Chakri dynasty. The Samuhanayoks of the Rattanakosin period were then not known as "Chaophraya Chakkri", which was the generic title of Samuhanayok, but instead known from their individualized title names, most famously Chaophraya Bodindecha.
By the late nineteenth century, the Chatusadom system was inadequate for the modernizing Siam. King Chulalongkorn and Prince Damrong gradually re-organized and transformed the Chatusadom ministries into the ministries in modern, Western sense. Firstly, the Phraklang ministry was separated into the Ministry of Finance and Ministry of Foreign Affairs in 1875. Each ministry was called Krasuang () instead of Krom, which became a term for subordinate departments. The reforms culminated in 1892 when King Chulalongkorn announced the official establishment of modern Cabinet comprising twelve ministries on April 1, 1892. The Krom Mahatthai of Samuhanayok became the Ministry of Interior and Krom Kalahom became the Ministry of Defence, thus ending the Chatusadom system.
See also
*Thai nobility *Sakdina *List of samuhanayok *List of samuhakalahom