# Regent of Thailand

In Thailand, the regent (Thai: ผู้สำเร็จราชการแทนพระองค์) is a person who exercises the official functions of a monarch of Thailand when the monarch is incapable of functioning or during a period of interregnum.

## Appointment
### By Old Royal Customs

Ancient custom dictates that the heir to the last king rule only as a regent and not as a king until he is officially consecrated. An unconsecrated king is not considered qualified to carry out the divine and priestly function of a Devarāja (or God-king). Until the coronation rites are completed the new king must exclude the prefix Phrabat (พระบาท) from his royal title, he cannot enact a royal command, nor sit under the nine-tiered umbrella (he must make do with only seven tiers). As a result, it was customary for a king to go through the coronation ceremonies as soon as he had succeeded to the throne.

### In Modern Era

According to the constitution of Thailand 2017 [th], there might be a regent when the monarch is unable to function and there will be a regent when the throne is vacant.

#### Incapacity of monarch

In accordance with the 2017 constitution, if the monarch is to leave the country or is unable to perform his duties for whatever reason, he may appoint any regent or council of regency. If he does make an appointment, the president of the National Assembly of Thailand will countersign the appointment.
If the monarch does not or cannot appoint any regent due to his minority or for any other reason and the Privy Council of Thailand finds the regency is necessary, the Privy Council will nominate a regent or council of regency to the president of the National Assembly for further appointment in the name of the monarch. The nominees are required to be those having been picked beforehand by the monarch and they must be nominated in accordance with the order of precedence designated beforehand by the monarch also.
Until a regent or council of regency is appointed, the president of the Privy Council will serve as the regent ad interim.
The constitution also requires an appointed regent to take the following oath of office amongst the National Assembly before assuming office:
Formerly, the law required regency during the incapacity of the monarch. In January 2017, King Rama X made an unprecedented move to change a draft constitution (later promulgated as the 2017 constitution) by removing the need for the monarch to appoint any regent in such an event, despite the draft having already been approved in a referendum.

#### Interregnum

In accordance with the 2017 constitution, when the throne becomes vacant, the president of the Privy Council of Thailand will act as the regent ad interim until a monarch is installed.
But if the vacancy takes place when there already is a regent, appointed by the previous monarch or by the president of the National Assembly due to the monarch's incapacity, that regent will continue to function until a monarch is enthroned. If the appointed regent is unable to function, the president of the Privy Council will also serve as the regent ad interim.

## Flag

The regent is given an official flag by the Flag Act 1979. It is a white square flag with a shield of the national flag at the centre, topped by the mythological bird garuda, which is the national emblem of Thailand.

## List of regents
### Fourth Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Mongkut (Rama IV) |||||
| | Somdet Chao Phraya Borom Maha Prayurawongse (Tish Bunnag) | 1851 | 1855 | The post established for the first time in Rattanakosin era. Appointed as a sinecure, functionally as prime minister. |

### Fifth Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Chulalongkorn (Rama V) |||||
| | Somdet Chao Phraya Borom Maha Sri Suriwongse (Chuang Bunnag) | 1 October 1868 | 16 November 1873 | Appointed regent by the Council of Ministers, until the king reached his majority at the age of 20. |
| | Queen Saovabha Phongsri | 7 April 1897 | 16 December 1897 | Appointed regent for the duration of the king's first visit to Europe. After the king's return, her title was elevated to Queen Regent. |
| | Crown Prince Maha Vajiravudh | 27 March 1907 | 17 November 1907 | Appointed regent for the duration of the king's second visit to Europe. |

### Sixth Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Vajiravudh (Rama VI) |||||
| | Prince Prajadhipok Sakdidej, the Prince of Sukhothai | 1925 | 25 November 1925 | Appointed regent during the illness of the king, after the king's death on 25 November 1925, himself succeeded to the throne as King Rama VII. |

### Seventh Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Prajadhipok (Rama VII) |||||
| | Prince Paribatra Sukhumbandhu, the Prince of Nakhon Sawan | 9 April 1932 | 8 May 1932 | Appointed regent for the duration of the king's summer holiday in Hua Hin, Prachuap Khiri Khan Province. |
| | Prince Chitcharoen, the Prince Narisara Nuwattiwong | 12 January 1934 | 2 March 1935 | Appointed regent while the king visited Europe for medical treatment, regency ended with the king's abdication of the throne. |

### Eighth Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Ananda Mahidol (Rama VIII) |||||
| | Cabinet of Siam acting as regency council pro tempore | 2 March 1935 | 7 March 1935 | The Cabinet of Siam filled-in as a regency council pro tempore during a brief interregnum in according to Constitution of Siam 1935 |
| | Prince Oscar Anuvatana | 7 March 1935 | 12 August 1935 | Appointed president of the three members regency council, during the king's minority (10 years of age at the time) and absence, as he was living in Switzerland. Died in office (committed suicide). |
| | Prince Aditya Dibabha | 7 March 1935 | 31 July 1944 | Succeeded Prince Oscar as president. Later resigned from office and ceased to be regent, died in 1945. |
| | Chao Phraya Yomarath (Pan Sukhum) | 7 March 1935 | 30 December 1938 | Died in office |
| | Chao Phraya Bijayendra Yodhin (General Um Indrayodhin) | 21 August 1935 | 21 July 1942 | Appointed regent to replace Prince Oscar. Died in office. |
| | Luang Praditmanutham (Pridi Banomyong) | 16 December 1941 | 20 September 1945 | Appointed regent to replace Chao Phraya Yomarath, previously held office as Minister of Finance. After the resignation of Prince Aditya Dibabha became the sole regent, until the return of the king in 1946. Later became the 7th prime minister of Thailand in 1946. |

### Ninth Reign

| Portrait | Name | Date of Appointment | Ceased to be Regent | Note |
| King Bhumibol Adulyadej (Rama IX) |||||
| | Regency council pro tempore under the Senate of Siam | 9 June 1946 | 16 June 1946 | After the death of Ananda Mahidol, 3 most senior senators were given the power of regency pro tempore under the Constitution of 1946 until the appointment of permanent regency council The regency council was composed of: 1. Phra Suthammavinijchai 2. Praya Nonrajasuvaj 3. Sanguan Juthathemi |
| | Prince Rangsit Prayurasakdi, the Prince of Chainat | 16 June 1946 | 7 November 1947 | Appointed two person regency council, when the king decided to return to his studies at the University of Lausanne in Switzerland. |
| | Phraya Manavaratsevi (Plod Vichear na Songkhla) | 16 June 1946 | 7 November 1947 | Appointed two person regency council, when the king decided to return to his studies at the University of Lausanne in Switzerland. |
| | Regency under the Privy Council | 9 November 1947 | 23 January 1949 | After the Siamese coup d'état of 1947 a new Privy Council was created and was given the power of regency under the Temporary Constitution of 1947. The council was composed of: 1. Prince Rangsit Prayurasakdi, the Prince of Chainat 2. Prince Dhani Nivat, the Prince Bidyalabh Bridhyakon 3. Prince Alongkot, the Prince Adireksorn Udomsakdi 4. Phraya Manavaratsevi (Plod Vichear na Songkhla) 5. General Adun Adundetcharat (Bat Phuengphrakhun) The council was relieved of the regency with the promulgation of the 1949 Constitution. |
| | Prince Rangsit Prayurasakdi, the Prince of Chainat | 23 June 1949 | Late 1949 | Appointed sole regent by recommendation of the National Assembly. Regency ended when the king returned to Thailand for his coronation ceremony on 5 May 1950. |
| | Prince Rangsit Prayurasakdi, the Prince of Chainat | 5 June 1950 | 7 March 1951 | Appointed regent during the king's travel and stay in Switzerland. Died in Office. |
| | Prince Dhani Nivat, the Prince Bidyalabh Bridhiyakon | 12 March 1951 | 29 November 1952 | Replace Prince Rangsit as regent. Regency ends after the abolition of constitution of Thailand 1949 |
| | Coup Group in charge as the Cabinet of Thailand acting as regency council pro tempore | 29 November 1952 | 3 December 1952 | Coup Group acted as the Cabinet of Thailand filled-in a regency council duty in according to Constitution of Siam 1935 Regency ends after the King returns to Thailand. |
| | Queen Sirikit of Thailand | 22 October 1956 | 5 November 1956 | Appointed regent during the king's absence as a Bhikkhu monk in the Buddhist Sangha (at Wat Bowonniwet Vihara). Afterwards, her title was elevated to Queen Regent. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 18 December 1959 | 21 December 1959 | State visit to the Republic of Vietnam by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 9 February 1960 | 16 February 1960 | State visit to the Republic of Indonesia by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 2 March 1960 | 5 March 1960 | State visit to the Union of Burma by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 14 June 1960 | 1960 | State visit to the United States of America and European countries by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 11 March 1962 | 22 March 1962 | State visit to the Islamic Republic of Pakistan by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 20 June 1962 | 27 June 1962 | State visit to the Federation of Malaya by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 17 August 1962 | 13 September 1962 | State visit to New Zealand and Australia by the king and queen. |
| | Prince Dhani Nivat, the Prince Bidyalabh Bridhiyakon (President of the Privy Council) | 27 May 1963 | 6 June 1963 | State visit to Japan and Republic of China by the king and queen. |
| | Prince Dhani Nivat, the Prince Bidyalabh Bridhiyakon (President of the Privy Council) | 9 July 1963 | 14 July 1963 | State visit to the Philippines by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 12 September 1964 | 6 October 1964 | Visit to the Kingdom of Greece on the occasion of the marriage of King Constantine II and Anne-Marie of Denmark and the state visit to the Republic of Austria by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 15 July 1966 | 1966 | State visit to the United Kingdom by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 23 April 1967 | 30 April 1967 | State visit to the Imperial State of Iran by the king and queen. |
| | Princess Srinagarindra, the Princess Mother of Thailand | 6 June 1967 | 1967 | State visit to the United States of America and Canada by the king and queen. |

### Tenth Reign

| Portrait | Name | Date of commencement | Ceased to be Regent | Note |
| King Vajiralongkorn (Rama X) |||||
| | General Prem Tinsulanonda | 13 October 2016 | 1 December 2016 | As the President of the Privy Council he became regent pro tempore upon the death of King Bhumibol Adulyadej under Constitution of the Kingdom of Thailand (Interim) 2014 This period was technically considered as an interregnum as Vajiralongkorn did not proclaim until 1 December and functioned as the crown prince in all royal ceremonies. Legally served during the first seven weeks of King Vajiralongkorn's reign. |