Chatusadom or Catustambha ( , literally "Four Pillars" from
Sanskrit
Sanskrit (; stem form ; nominal singular , ,) is a classical language belonging to the Indo-Aryan languages, Indo-Aryan branch of the Indo-European languages. It arose in northwest South Asia after its predecessor languages had Trans-cultural ...
''Catur'' "Four" + ''Stambha'' "Pillars") was the Thai system of central executive governance during the
Ayutthaya Kingdom
The Ayutthaya Kingdom or the Empire of Ayutthaya was a Thai people, Thai kingdom that existed in Southeast Asia from 1351 to 1767, centered around the city of Phra Nakhon Si Ayutthaya (city), Ayutthaya, in Siam, or present-day Thailand. Europe ...
,
Thonburi Kingdom
The Thonburi Kingdom was a major Thai people, Siamese kingdom which existed in Southeast Asia from 1767 to 1782, centered around the city of Thonburi, in Siam or present-day Thailand. The kingdom was founded by Taksin, who reunited Siam follow ...
and
Rattanakosin Kingdom from 1454 to 1892. For about four hundred years, it had served as the constitution of central government of
Siam
Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
or
Thailand
Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
until King
Chulalongkorn
Chulalongkorn (20 September 1853 – 23 October 1910), posthumously honoured as King Chulalongkorn the Great, was the fifth king of Siam from the Chakri dynasty, titled Rama V. Chulalongkorn's reign from 1868 until his death in 1910 was cha ...
organized ''Chatusadom'' into modern
ministries
Ministry may refer to:
Government
* Ministry (collective executive), the complete body of government ministers under the leadership of a prime minister
* Ministry (government department), a department of a government
Religion
* Christian mi ...
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
Phutthayotfa Chulalok (born Thongduang; 20 March 1737 – 7 September 1809), also known by his regnal name Rama I, was the founder of the Rattanakosin Kingdom (now Thailand) and the first King of Siam from the reigning Chakri dynasty. He asce ...
enacted the Palatine Law in the
Three Seals Law
The ''Three Seals Law'' or ''Three Seals Code'' (; ) is a collection of law texts compiled in 1805 on the orders of King Rama I of Siam. Most of the texts were laws from the Ayutthaya era which had survived the destruction of Ayutthaya in 1767. ...
,
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''.
History and subsequent amendments
The Four Ministries of ''Chatusadom'' or ''Wiang-Wang-Khlang-Na'' had existed in
Ayutthaya
Ayutthaya, Ayudhya, or Ayuthia may refer to:
* Ayutthaya Kingdom, a Thai kingdom that existed from 1350 to 1767
** Ayutthaya Historical Park, the ruins of the old capital city of the Ayutthaya Kingdom
* Phra Nakhon Si Ayutthaya province (locall ...
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 Four Ministers were raised to the rank of ''Phraya'' and the Ministries were given Sanskrit-derived names. The executives was led by two prime ministers; the ''Samuhanayok'' and the ''Samuhakalahom'', who performed administrative duties on behalf of the king in Civil and Military Affairs, respectively. The officials were divided into Civil and Military divisions. However, as time progressed, the distinction between Civil and Military divisions became blurred and all official including Civil officials were expected to perform military duties especially during the wars. The two prime ministers and four ministers had their own offices and each office had a long list of functionaries.
After King Trailokanat, auxiliary departments were added to the apparatus to meet the demands. King
Ramathibodi II
Chettathirat (, ) or (upon accession to the Ayutthayan throne) Ramathibodi II (; 1472/73 – July/10 October 1529) was the King of Sukhothai from 1485 and King of Ayutthaya from 1491 to 1529. His reign was marked by the first Western Contact wit ...
established the ''Krom Phra Suratsawadi'' () or the Registration Department in 1518 to specifically oversee the census of manpower for more efficient levy and conscription. After the conclusion of a trade treaty with the Portuguese in 1511, ''Phra Khlang Sinkha'' () or Royal Warehouse was established within the Ministry of Treasury to deal with foreign trades, in which the royal court held the monopoly. In the seventeenth century, the trade with Western nations grew and the ''Krommatha'' () or the Ministry of Pier, formerly a department within the Ministry of Treasury, rose to importance and the term ''Krommatha'' became quite synonymous with ''Krommakhlang''.
The position of ''Samuhakalahom'' had grown powerful by the mid-Ayutthaya period as he controlled military forces. ''Okya'' Kalahom Suriyawongse the ''Samuha Kalahom'' usurped the throne and ascended as King
Prasat Thong
Prasat ThongThe Royal Institute. List of monarchs Ayutthaya''. (, ; c. 1599–1655; 1629–1655) was the first king of the Prasat Thong dynasty, the fourth dynasty of the Siamese Ayutthaya Kingdom. Before being king, he defeated a rebellion led ...
in 1629. The power imbalance and potential threat from some ministers led the kings to reconsider and amend the ''Chatusadom'' bureaucracy. King Prasat Thong transferred the Cavalry and Elephant Regiments from ''Samuha Kalahom'' to ''Samuha Nayok''. Some kings preferred not to appoint ''Samuhanayok'' or ''Samuhakalahom'' to avoid creating powerful nobles, most notably King
Narai
King Narai the Great (, , ) or Ramathibodi III ( ) was the 27th monarch of Ayutthaya Kingdom, the 4th and last monarch of the Prasat Thong dynasty. He was the king of Ayutthaya Kingdom from 1656 to 1688 and arguably the most famous king of the ...
, who instead assigned the duties and responsibilities of the two prime ministers to his ministers without officially investing them with titles and honors.

The greatest reform of ''Chatusadom'' came during the reign of King
Phetracha
Phetracha (alternative spellings: ''Bedraja'', ''P'etraja'', ''Petraja'', ''Petratcha''; also called ''Phra Phetracha''; , ; 1632– 5 February 1703) was a king of the Ayutthaya Kingdom, usurping the throne from his predecessor King Narai and orig ...
. King Phetracha, who faced rebellions in
Nakhon Ratchasima
Nakhon Ratchasima (, ) is the capital of Nakhon Ratchasima province, the largest city in Isan, Northeastern Thailand and the List of municipalities in Thailand#Largest cities by urban population, third-largest city in Thailand. It is 250 km (1 ...
and
Nakhon Si Thammarat
Nakhon Si Thammarat (, ; from ) is a city municipality (''thesaban nakhon'') located in Mueang Nakhon Si Thammarat, the capital of Nakhon Si Thammarat Province. Nakhon Si Thammarat Province is situated in the South of Thailand. It is about s ...
that took nearly three years to quell, sought to reduce the power of regional governors. He expanded the authority of ''Chatusadom'' to the regional level and redefined the two prime ministers. The ''Samuha Nayok'' became the Prime Minister of Northern Siam in both Civil and Military affairs while the ''Samuha Kalahom'' became the Prime Minister of Southern Siam.
The division between the two prime ministers went from "functional" to "regional". King Phetracha also assigned the coastal port cities to the ''Krommatha''. Siam was then divided among the three ministers and the city governors were to report to the minister of their respective regions. The Minister of Trade or "Phraklang" also grown exceptionally powerful due to participation in foreign trades. By the eighteenth century in the Late Ayutthaya, three most powerful ministers of Siam were the ''Samuhanayok'', the ''Samuhakalahom'' and Phraklang the Minister of Trade.
King
Borommakot
King Borommakot (, ) or King Maha Thammarachathirat II () was the king of Ayutthaya from 1733 to 1758. His reign was the last blooming period of Ayutthaya as the kingdom would fall nine years after his death.Chakrabongse, C., 1960, Lords of Life, ...
, who ascended the throne in 1733 after a civil war with his nephews, transferred the cities of the ''Samuha Kalahom'' who had declared neutrality in the civil war to
''Chaophraya'' Chamnanborirak the Minister of Trade who was his ardent supporter. The Southern Siamese cities were then transferred from ''Kalahom'' to ''Krommatha''.
The ''Samuhakalahom'' became a powerless figure. After the Fall of Ayutthaya in 1767, Thonburi and Rattanakosin kingdoms inherited the whole ''Chatusadom'' apparatus of the Late Ayutthaya period. King
Rama I
Phutthayotfa Chulalok (born Thongduang; 20 March 1737 – 7 September 1809), also known by his regnal name Rama I, was the founder of the Rattanakosin Kingdom (now Thailand) and the first King of Siam from the reigning Chakri dynasty. He asc ...
restored the Southern Siamese cities to the authority of ''Samuha Kalahom'' in 1782.
The seals of top three ministers were stamped on the
Three Seals Law
The ''Three Seals Law'' or ''Three Seals Code'' (; ) is a collection of law texts compiled in 1805 on the orders of King Rama I of Siam. Most of the texts were laws from the Ayutthaya era which had survived the destruction of Ayutthaya in 1767. ...
. King Rama I who was formerly ''Chaophraya'' Chakkri the ''Samuha Nayok'' established the
Chakri dynasty
The Chakri dynasty is the current reigning dynasty of the Thailand, Kingdom of Thailand. The head of the house is the Monarchy of Thailand, king, who is head of state. The family has ruled Thailand since the founding of the Rattanakosin era and ...
. The ''Samuhanayok''s 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
''Chao Phraya'' Bodindecha (, , 13 January 1776 – 24 June 1849), personal name Sing Sinhaseni (), was a prominent military figure of the early Rattanakosin Kingdom period during the reign of King Rama III. Bodindecha hold the post of ''Samuh ...
.
By the late nineteenth century, the ''Chatusadom'' system was inadequate for the modernizing Siam. King
Chulalongkorn
Chulalongkorn (20 September 1853 – 23 October 1910), posthumously honoured as King Chulalongkorn the Great, was the fifth king of Siam from the Chakri dynasty, titled Rama V. Chulalongkorn's reign from 1868 until his death in 1910 was cha ...
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
A ministry of finance is a ministry or other government agency in charge of government finance, fiscal policy, and financial regulation. It is headed by a finance minister, an executive or cabinet position .
A ministry of finance's portfoli ...
and
Ministry of Foreign Affairs
In many countries, the ministry of foreign affairs (abbreviated as MFA or MOFA) is the highest government department exclusively or primarily responsible for the state's foreign policy and relations, diplomacy, bilateral, and multilateral r ...
in 1875. Each ministry was called ''Krasuang'' ({{langx, th, กระทรวง) 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
An interior ministry or ministry of the interior (also called ministry of home affairs or ministry of internal affairs) is a government department that is responsible for domestic policy, public security and law enforcement.
In some states, th ...
and ''Krom Kalahom'' became the
Ministry of Defence
A ministry of defence or defense (see American and British English spelling differences#-ce.2C -se, spelling differences), also known as a department of defence or defense, is the part of a government responsible for matters of defence and Mi ...
, thus ending the ''Chatusadom'' system.
See also
*
Thai nobility
The Thai nobility was a social class comprising titled officials (''khunnang'', ) in the service of the monarchy. They formed part of a hierarchical social system which developed from the time of the Ayutthaya Kingdom (14th century – 1767), thro ...
*
Sakdina
''Sakdina'' () was a system of social hierarchy in use from the Ayutthaya to early Rattanakosin periods of Thai history. It assigned a numerical rank to each person depending on their status, and served to determine their precedence in society, an ...
*
List of samuhanayok
The ''samuhanayok'' () was one of the two chief ministers in the historical Chatusadom government system of Siam (now Thailand), originally charged with civil affairs but later overseeing both civil and military affairs in northern cities. During ...
*
List of samuhakalahom
The ''samuhakalahom'' () was one of the two chief ministers in the historical Chatusadom government system of Siam (now Thailand) in use from the Ayutthaya through early Rattanakosin periods. The post was originally charged with military affairs ...
References
15th-century establishments in Thailand
1892 disestablishments in Siam
Political history of Thailand
Ayutthaya Kingdom