List of Thai monarchs

King of Thailand
พระมหากษัตริย์ไทย
Royal Standard (since 1910)
Incumbent
Vajiralongkorn (Rama X) since 13 October 2016
Details
Style	His Majesty
Heir presumptive	Dipangkorn Rasmijoti
First monarch	Si Inthrathit
Formation	1238; 786 years ago (1238)
Residence	Grand Palace (ceremonial) Dusit Palace (residential)
Website	royaloffice.th

The succession of Thai monarchs began with Si Inthrathit at the establishment of the first Thai kingdom in 1238. With brief interruptions, 55 monarchs have ruled over four successive kingdoms, the current monarch being Vajiralongkorn (Rama X) of the Chakri dynasty.

In the Sukhothai Kingdom, the monarch used the title Pho Khun (Thai: พ่อขุน), and monarchs who reigned over the period of decline after Ram Khamhaeng the Great used the title Phraya (Thai: พญา).

In the Ayutthaya Kingdom and afterward, thanandon, the system of Thai royal titles, determines the style of the monarch's full regnal name (which includes the title), consisting of two interconnected parts:

• The first part is the title Phra Bat Somdet Phra Chao Yu Hua (Thai: พระบาทสมเด็จพระเจ้าอยู่หัว, 'His Majesty the King'). The title is split by the regnal name, written between Phra and Chao. If the monarch was not formally crowned, Phra Bat is omitted. If the monarch ruled as a tributary or was usurped, Somdet may be omitted.
  • Sometimes, Chao Yu Hua is fully omitted. Other times, only Yu Hua is omitted, in which case Chao follows the remaining components of the title and precedes the regnal name.
• The second part is the regnal name, of which only a portion may be used to commonly refer to the monarch. It may differ from their birth name, their name as uparaja (viceroy), or their posthumous name and/or historical style. This list refers to monarchs by the names most often used by traditional historians.^[1]

Western nations referred to the monarch as the "King of Siam" (Latin: Rex Siamensium), regardless of Thai titles, since the initiation of relations in the 16th century. Mongkut (Rama IV) was the first monarch to adopt the title when the name Siam was first used in an international treaty.^[2] When the kingdom's name was changed to Thailand, the monarch's Western title changed accordingly.^[3]

Tai peoples migrated into mainland Southeast Asia in the 8th–10th centuries.^[4] In the years after, Northern Thai groups established mueang that evolved into larger states, such as Ngoenyang.^[5][6] However, it was not until the decline of the Khmer Empire in the 13th century that a Central Thai kingdom politically and culturally related to modern Thailand was first founded.

The Phra Ruang dynasty was the only royal lineage that ruled over the Sukhothai Kingdom, the first Central Thai state. Established by Si Inthrathit in 1238, who declared independence from the Khmer Empire, the dynasty laid the foundations for Thai society.^[7] Under Ram Khamhaeng the Great, the initial Thai script was invented and Therāvada Buddhism was established as the state religion.^{[8]: 197 [9]: 25}

The dynasty is named after the Traiphum Phra Ruang, a Buddhist cosmology book written by Maha Thammaracha I. During his reign, the kingdom was invaded by Ayutthaya, a neighboring Thai state, becoming a tributary during the reign of Maha Thammaracha II.^[8]: 222

In the Sukhothai Kingdom, the monarch ruled from the city of Sukhothai, while the heir presumptive would occasionally be named uparaja, or viceroy, and ruled in Si Satchanalai. In 1438, Ayutthaya annexed Sukhothai at the death of Maha Thammaracha IV when Borommarachathirat II of Ayutthaya named his son Prince Ramesuan uparaja. In Ayutthaya, the tradition would evolve into the Front Palace system.^[10]

No.	Portrait	Regnal name	Personal name	Reign	Succession	Life details
1		Kamonteng Ansi Inthrabodinthrathit กมรเตงอัญศรีอินทรบดินทราทิตย์	Pho Khun Si Inthrathit พ่อขุนศรีอินทราทิตย์ or Pho Khun Bang Klang Hao พ่อขุนบางกลางหาว	1238 – 1270 (32 years)	First King of Sukhothai	1188 – 1270 (aged 82) Ruled locally in the Khmer Empire as Bang Klang Hao. His rebellion led to the establishment of Sukhothai, the first Central Thai kingdom[7]
2		Pho Khun Ban Mueang พ่อขุนบานเมือง		1270 – 1279 (9 years)	Son of Si Inthrathit	c. 1237 – 1279 (aged approx. 42) Namesake for birth name of Maha Thammaracha IV[11]
3		Phrabat Kamonteng Ansi Rammarat พระบาทกมรเตงอัญศรีรามราช	Pho Khun Ram Khamhaeng the Great พ่อขุนรามคำแหงมหาราช	1279 – 1298 (19 years)	Younger brother of Ban Mueang; named uparaja	c. 1237/1247 – 1298 (aged approx. 51/61) Oversaw the height of Sukhothai prosperity, the development of the Thai script, and the propagation of Theravada Buddhism within Sukhothai[8]
4		Phraya Loe Thai พระยาเลอไทย		1298 – 1323 (25 years)	Son of Ram Khamhaeng	c. 1262 – 1323 (aged approx. 61) Brother of Burmese queen consort May Hnin Thwe-Da.[12] His reign saw the decline of Sukhothai, as regions conquered by Ram Khamhaeng broke away
5		Phraya Ngua Nam Thum พระยางั่วนำถุม		1323 – 1347 (24 years)	Son of Ban Mueang and first cousin of Loe Thai	c. 1266 – 1347 (aged approx. 81) Brother of Burmese queen consort May Hnin Htapi.[13] Origin of his name is disputed[14]
6		Phra Maha Thammaracha I พระมหาธรรมราชาที่ ๑	Phraya Li Thai พระยาลิไทย	1347 – 1368 (21 years)	Son of Loe Thai and first cousin once removed of Ngua Nam Thum; named uparaja as Li Thai in 1340/41[11]	c. 1300 – 1368 (aged approx. 68) Known for his devotion to Buddhist philosophy and writing.[9] During his reign, Ayutthaya began to invade into Sukhothai[8]
1378: Sukhothai became a tributary state of the Ayutthaya Kingdom.
7		Phra Maha Thammaracha II พระมหาธรรมราชาที่ ๒	Phraya Lue Thai พระยาลือไทย	1368 – c. 1400 (approx. 32 years)	Son of Maha Thammaracha I	c. 1358 – 1400 (aged approx. 42) Born Lue Thai. Under his rule, the dynasty continued under tributary status[8]
8		Phra Maha Thammaracha III พระมหาธรรมราชาที่ ๓	Phraya Sai Lue Thai พระยาไสลือไทย	c. 1400 – 1419 (approx. 19 years)	Son of Maha Thammaracha II	c. 1380 – 1419 (aged approx. 39) Born Sai Lue Thai
9		Phra Maha Thammaracha IV พระมหาธรรมราชาที่ ๔	Phraya Borommapan พระยาบรมปาล	1419 – 1438 (19 years)	Son of Maha Thammaracha III	c. 1401 – 1438 (aged approx. 37) Born Borommapan. Won the throne against his brother after the intervention of King Intharachathirat of Ayutthaya.[15] Upon his death, King Borommarachathirat II of Ayutthaya installed his son as uparaja, ending the Phra Ruang succession[10]
1438: Unification with Ayutthaya Kingdom ended Sukhothai autonomy.

The Aytthaya Kingdom was a result of a unification between two states: the Kingdom of Suphannaphum (Suphanburi) and the Kingdom of Lavo. Though the Kingdom of Lavo was originally a Mon kingdom, the migration of the Tai peoples into the Chao Phraya basin replaced the original Mons, consequently becoming the governors of these regions. This resulted in the capital moving from Lavapura (Lopburi) and Suphannaphum (Suphanburi) to Ayodhya (Old Ayutthaya), a new capital.^[16] Later on, the Kingdom of Nakhon si Thammarat came under the influence of Ayutthaya after seceding from Sukhothai, and Sukhothai losing influence and coming under Ayutthayan influence.

This conflict would last long into the history of Ayutthaya Kingdom, where families from the four major regional kingdoms vie over the throne of the kingdom. These kingdoms are: Kingdom of Nakhon Si Thammarat, Kingdom of Sukhothai, Kingdom of Lavo, and Kingdom of Suphannaphum. The Kingdom of Sukhothai was integrated into the Kingdom of Ayutthaya along with its noble famlies.^[17]

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes
1		Somdet Phra Ramathibodi I สมเด็จพระรามาธิบดีที่ ๑	Phra Chao Uthong พระเจ้าอู่ทอง	3 April 1314	4 March 1351[20]	1369 (18 years) (63 years old)		First King of Ayutthaya
2		Somdet Phra Ramesuan สมเด็จพระราเมศวร		1339	1369	1370 (less than one year) (abdicated)	1395 (56 years old)	Son of Uthong

As previously mentioned, the kingdom of Ayutthaya was the result of the unification between two federations: Lavo and Suphannaphum. The ruling dynasty of Lavo gave rise to the Uthong Dynasty, in which the Suphannaphum dynasty came from the Suphannaphum federation. This federation held significant influence within the kingdom leading them to take control of the throne in 1310.

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes
3		Somdet Phra Borommarachathirat I สมเด็จพระบรมราชาธิราชที่ ๑	Khun Luang Pha Ngua ขุนหลวงพะงั่ว	1310	1370	1388 (18 years) (78 years old)		Usurper, former Lord of Suphanburi Husband of Uthong's older sister Possible son of Uthong III, making him a great-great-great-grandson of Phrom
4		Somdet Phra Chao Thong Lan สมเด็จพระเจ้าทองลัน		1374	1388 (7 days) (14 years old)			Son of Borommarachathirat I

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes
(2)		Somdet Phra Ramesuan สมเด็จพระราเมศวร		1339	1388	1395 (7 years) (56 years old)		Former king reclaiming the throne Son of Uthong
5		Somdet Phra Ramrachathirat สมเด็จพระรามราชาธิราช	Somdet Phraya Ram Chao สมเด็จพญารามเจ้า	1356	1395	1409 (14 years) (usurped)	?	Son of Ramesuan

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes	Viceroy
6		Somdet Phra Intharachathirat สมเด็จพระนครินทราธิราช	Chao Nakhon In เจ้านครอินทร์	1359	1409	1424 (15 years) (65 years old)		Former Lord of Suphanburi, offered crown Nephew or son of Borommarachathirat I
7		Somdet Phra Borommarachathirat II สมเด็จพระบรมราชาธิราชที่ ๒	Chao Sam Phraya เจ้าสามพระยา	1386	1424	1448 (24 years) (62 years old)		Son of Intharachathirat	Ramesuan (son)
8		Somdet Phra Borommatrailokkanat สมเด็จพระบรมไตรโลกนาถ	Phra Ramesuan (II) พระราเมศวร (ที่๒)	1431	1448	1488 (40 years) (57 years old)		Son of Borommarachathirat II	Chettha (son)
Administrative reform Chatusadom, 1454
9		Somdet Phra Borommarachathirat III สมเด็จพระบรมราชาธิราชที่ ๓	Phra Borommaracha พระบรมราชา	1462	1488	1491 (3 years) (29 years old)		Son of Borommatrailokkanat	Chettha (brother)
10		Somdet Phra Ramathibodi II สมเด็จพระรามาธิบดีที่ ๒	Phra Chetthathirat พระเชษฐาธิราช	1473	1491	10 October 1529 (38 years) (56 years old)		Younger brother of Borommarachathirat III Son of Borommatrailokkanat	Athittayawong (son)
11		Somdet Phra Borommarachathirat IV สมเด็จพระบรมราชาธิราชที่ ๔	Phra Athittayawong พระอาทิตยวงศ์	1488	10 October 1529	1533 (4 years) (45 years old)		Son of Ramathibodi II	Chairacha (brother)
12		Somdet Phra Ratsadathirat สมเด็จพระรัษฎาธิราช		1529	1533 (5 months) (4 years old)			Son of Borommarachathirat IV Child king, reigned under regency	Vacant
13		Somdet Phra Chairachathirat สมเด็จพระไชยราชาธิราช		1499	1533	1546 (13 years) (47 years old)		Usurper, uncle of Ratsadathirat Younger brother of Borommarachathirat IV Son of Ramathibodi II
14		Somdet Phra Yotfa สมเด็จพระยอดฟ้า		1535	1546	1548 (2 years) (usurped)	10 June 1548 (13 years old)	Son of Chairachathirat
—		Khun Worawongsathirat ขุนวรวงศาธิราช	Bunsi บุญศรี	1503	before 10 June 1548	11 November 1548 – 5 January 1549 (154 days) (45 years old)		Usurper, not accepted by some historians	Chan (brother)
15		Somdet Phra Maha Chakkraphat สมเด็จพระมหาจักรพรรดิ	Phra Chao Chang Pheuak พระเจ้าช้างเผือก or Phra Thianracha พระเทียรราชา	1509	1548	1568 (20 years) (59 years old)		Son of Ramathibodi II Younger brother of Borommarachathirat IV and Chairachathirat Seized the throne from a usurper Became a Buddhist monk at Pegu (1564–1568), resumed power	Ramesuan (son)
									Mahin (son)
16		Somdet Phra Mahinthrathirat สมเด็จพระมหินทราธิราช		1539	1568	2 August 1569 (1 year) (deposed)	c. late 1569 (30 years old)	Son of Maha Chakkraphat and Queen Suriyothai	Vacant
First Fall of Ayutthaya

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes	Viceroy
Vassal of the First Toungoo Empire (1569–1584)
17		Somdet Phra Sanphet I สมเด็จพระสรรเพชญ์ที่ ๑	Somdet Phra Maha Thammarachathirat สมเด็จพระมหาธรรมราชาธิราช	1517	1569	c. 30 June 1590 (21 years) (73 years old)		Former Lord of Phitsanulok Descended from the Phra Ruang dynasty of Sukhothai Son-in-law of Maha Chakkraphat and Queen Suriyothai Installed as vassal of Bayinnaung of the Toungoo Empire, declared independence in 1584	Naresuan (son)
Independence from the First Toungoo Empire, 1584
18		Somdet Phra Sanphet II สมเด็จพระสรรเพชญ์ที่ ๒	Somdet Phra Naresuan the Great สมเด็จพระนเรศวรมหาราช	1555/56	1 July 1590	25 April 1605 (15 years) (49 years old)		Son of Maha Thammarachathirat	Ekathotsarot (brother)
19		Somdet Phra Sanphet III สมเด็จพระสรรเพชญ์ที่ ๓	Somdet Phra Ekathotsarot สมเด็จพระเอกาทศรถ	1557	25 April 1605	1610 (5 years) (53 years old)		Brother of Naresuan Son of Maha Thammarachathirat	Suthat (son)
20		Somdet Phra Sanphet IV สมเด็จพระสรรเพชญ์ที่ ๔	Somdet Phra Si Saowaphak สมเด็จพระศรีเสาวภาคย์	1585	1610	1611 (1 year, 2 months) (26 years old)		Son of Ekathotsarot	Vacant
21		Somdet Phra Borommaracha I สมเด็จพระบรมราชาที่ ๑	Somdet Phra Songtham สมเด็จพระเจ้าทรงธรรม	1590	1611	12 December 1628 (17 years) (38 years old)		Son of Ekathotsarot, invited to take the throne after leaving the Sangha (priesthood)	Si Sorarak (son)
22		Somdet Phra Borommaracha II สมเด็จพระบรมราชาที่ ๒	Somdet Phra Chetthathirat สมเด็จพระเชษฐาธิราช	c. 1613	12 December 1628	1628–1629 (1 year) (16 years old)		Son of Songtham	Vacant
23		Somdet Phra Athittayawong สมเด็จพระอาทิตยวงศ์		1620	1629 (36 days) (usurped)		1637 (17 years old)	Younger brother of Chetthathirat Son of Songtham

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes	Viceroy
24		Somdet Phra Chao Sanphet V สมเด็จพระสรรเพชญ์ที่ ๕	Somdet Phra Chao Prasat Thong สมเด็จพระเจ้าปราสาททอง	1599	1629[21][22]	August 1655 (26 years) (56 years old)		Usurper, formerly the Kalahom Rumored to be a son of Ekathotsarot	Vacant
25		Somdet Phra Sanphet VI สมเด็จพระสรรเพชญ์ที่ ๖	Somdet Chao Fa Chai สมเด็จเจ้าฟ้าไชย	1630	August 1655	1656 (1 year) (26 years old)		Son of Prasat Thong
26		Somdet Phra Sanphet VII สมเด็จพระสรรเพชญ์ที่ ๗	Somdet Phra Si Suthammaracha สมเด็จพระศรีสุธรรมราชาธ	1600	August 1656	26 October 1656 (~2 months) (56 years old)		Usurper, uncle of Chai Younger brother of Prasat Thong	Narai (nephew)
27		Somdet Phra Ramathibodi III สมเด็จพระรามาธิบดีที่ ๓	Somdet Phra Narai the Great สมเด็จพระนารายณ์มหาราช	16 February 1632	26 October 1656	11 July 1688 (32 years) (56 years old)		Usurper, nephew of Si Suthammaracha Son of Prasat Thong Half-brother of Chai Former Front Palace	Vacant
The Siamese revolution of 1688; populist upheaval[23]

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes	Viceroy
28		Somdet Phra Phetracha สมเด็จพระเพทราชา	Somdet Phra Mahaburut สมเด็จพระมหาบุรุษ	1632	11 July 1688	5 February 1703 (14 years) (71 years old)		Usurper Former commander of the Elephant Corps Son-in-law of Narai	Sorasak (stepson)
29		Somdet Phra Sanphet VIII สมเด็จพระสรรเพชญ์ที่ ๘	Somdet Phra Suriyenthrathibodi สมเด็จพระเจ้าสุริเยนทราธิบดี or Phra Chao Seua พระเจ้าเสือ	1661	5 February 1703	9 February 1709 (7 years) (48 years old)		Stepson of Phetracha Biological son of Narai and Chiang Mai's Princess that was given to be Phetracha's wife later	Phet (son)
30		Somdet Phra Sanphet IX สมเด็จพระสรรเพชญ์ที่ ๙	Phra Chao Thai Sa พระเจ้าท้ายสระ	1679	9 February 1709	13 January 1733 (23 years) (54 years old)		Son of Suriyenthrathibodi	Phon (brother)
31		Somdet Phra Maha Thammarachathirat II สมเด็จพระมหา ธรรมราชาธิราชที่ ๒	Somdet Phra Chao Yu Hua Borommakot สมเด็จพระเจ้าอยู่หัวบรมโกศ	c. 1681[24]	13 January 1733	26 April 1758 (26 years) (77 years old)		Brother of Thai Sa Son of Suriyenthrathibodi Former Front Palace	Senaphithak (son)
									Phonphinit (son)
32		Somdet Phra Maha Thammarachathirat III สมเด็จพระมหา ธรรมราชาธิราชที่ ๓	Somdet Phra Chao Uthumphon สมเด็จพระเจ้าอุทุมพร	1733	1 May 1758	1758 (3 months)	1796 (~63 years old)	Son of Borommakot Former Front Palace	Vacant
33		Somdet Phra Borommaracha III สมเด็จพระบรมราชาที่ ๓	Somdet Phra Thinang Suriyat Amarin สมเด็จพระที่นั่งสุริยาศน์อมรินทร์ or Somdet Phra Chao Ekkathat สมเด็จพระเจ้าเอกทัศ	1718	1758	7 April 1767 (9 years)	17 April 1767 (49 years old)	Usurper, brother of Uthumphon Son of Borommakot
Second Fall of Ayutthaya

No.	Portrait	Regnal name	Personal name	Birth	Reign from	Reign until	Death	Notes	Viceroy
1		Somdet Phra Sanphet X สมเด็จพระสรรเพชญ์ที่ ๑๐ or Somdet Phra Borommaracha IV สมเด็จพระบรมราชาที่ ๔	Somdet Phra Chao Taksin the Great สมเด็จพระเจ้าตากสินมหาราช	17 April 1734	28 December 1767	1 April 1782 (14 years) (deposed) [25][26][a]	7 April 1782 (47 years old) (executed)[b]	Son of Yong Saetae, a Teochew Chinese family named "Tea" (鄭) or "Zheng" in Mandarin Chinese, and Thephamat Only King of Thonburi	Inthraphithak (son)
The coup seized power as the Rattanakosin Kingdom[28]

No.	Portrait	Regnal name	Personal name	Birth (Parents)	Accession (Coronation)	Reign until	Death	Notes	Viceroy
1		Somdet Phra Ramathibodi IV สมเด็จพระรามาธิบดีที่ ๔ (name originally taken) or Rama I พระรามที่ ๑ (รัชกาลที่ ๑) (retroactively given)	Phrabat Somdet Phra Paramoruracha Maha Chakri Boromanat Phra Phutthayotfa Chulalok the Great พระบาทสมเด็จพระปรโมรุราชามหาจักรีบรมนารถ พระพุทธยอดฟ้าจุฬาโลกมหาราช (posthumously by Rama III) or Somdet Chao Phraya Maha Kasatseuk สมเด็จเจ้าพระยามหากษัตริย์ศึก	20 March 1737 4th child (2nd son) of Thongdi and Daoreung	6 April 1782 (1st: 10 June 1782, 2nd: 17 June 1785)	7 September 1809 (27 years, 154 days) (72 years old)		Father-in-law of Taksin His father was a great-grandson of Kosa Pan, and his mother was the daughter of a Hokkien millionaire family. Through the female line, he claimed to be a descendant of the Sukhothai dynasty.	Maha Sura Singhanat (brother)
									Itsarasunthon (son)
2		Rama II พระรามที่ ๒ (รัชกาลที่ ๒) (retroactively given)	Phrabat Somdet Phra Boromratchapongchet Maha Itsarasunthon Phra Phutthaloetla Naphalai พระบาทสมเด็จพระบรมราชพงษเชษฐมเหศวรสุนทร พระพุทธเลิศหล้านภาลัย (posthumously by Rama III)	24 February 1767 4th child (2nd son) of Rama I and Queen Amarindra	7 September 1809 (17 September 1809)	21 July 1824 (14 years, 317 days) (57 years old)		Son of Rama I	Maha Senanurak (brother)
3		Rama III พระรามที่ ๓ (รัชกาลที่ ๓) (retroactively given)	Phrabat Somdet Phra Paramathiworaset Maha Chetsadabodin Phra Nangklao Chao Yu Hua พระบาทสมเด็จพระปรมาธิวรเสรฐมหาเจษฎาบดินทรฯ พระนั่งเกล้าเจ้าอยู่หัว (posthumously by Rama IV) or Phra Maha Chettha Chao พระมหาเจษฎาราชเจ้า	31 March 1788 3rd child (2nd son) of Rama II and 1st child of Consort Sri Sulalai	21 July 1824 (1 August 1824)	2 April 1851 (26 years, 255 days) (63 years old)		Son of Rama II His mother was a great-great-great-great-granddaughter of Sultan Sulaiman Shah of the Sultanate of Singora.	Sakdiphonlasep (uncle)
4		Rama IV พระรามที่ ๔ (รัชกาลที่ ๔) (retroactively given)	Phrabat Somdet Phra Poramenthra Ramathibodhi Srisindra Maha Mongkut Phra Chomklao Chao Yu Hua พระบาทสมเด็จพระปรเมนทรรามาธิบดีศรีสินทรมหามงกุฎ พระจอมเกล้าเจ้าอยู่หัว or Phra Sayam Thewa Maha Makut Witthaya the Great พระสยามเทวมหามกุฏวิทยมหาราช	18 October 1804 44th child (22nd son) of Rama II and 2nd child of Queen Sri Suriyendra	2 April 1851 (15 May 1851)	1 October 1868 (17 years, 182 days) (63 years old)		Half-brother of Rama III Son of Rama II	Pinklao (brother)
The feudal system was changed to absolute monarchy in 1892
5		Rama V พระรามที่ ๕ (รัชกาลที่ ๕) (retroactively given)	Phrabat Somdet Phra Poraminthra Maha Chulalongkorn Phra Chulachomklao Chao Yu Hua พระบาทสมเด็จพระปรมินทรมหาจุฬาลงกรณ์ฯ พระจุลจอมเกล้าเจ้าอยู่หัว or Phra Piya the Great พระปิยมหาราช (His full name is 979 characters long)	20 September 1853 9th child (5th son) of Rama IV and 1st child of Queen Debsirindra	1 October 1868 (1st: 11 November 1868, 2nd: 16 November 1873)	23 October 1910 (42 years, 22 days) (57 years old)		Son of Rama IV Under regency of Sri Suriwongse until 1873	Wichaichan (cousin)
									Viceroyalty abolished in 1885 after the Front Palace Crisis
6		Rama VI พระรามที่ ๖ (รัชกาลที่ ๖) (new regnal name)	Phrabat Somdet Phra Poramenthra Maha Vajiravudh Phra Mongkutklao Chao Yu Hua พระบาทสมเด็จพระปรเมนทรมหาวชิราวุธ พระมงกุฎเกล้าเจ้าอยู่หัว or Phra Maha Thirarat Chao พระมหาธีรราชเจ้า	1 January 1881 28th child (11th son) of Rama V and 2nd child of Queen Saovabha Phongsri	23 October 1910 (1st: 11 November 1910, 2nd: 28 November 1911)	26 November 1925 (15 years, 34 days) (44 years old)		Son of Rama V
7		Rama VII พระรามที่ ๗ (รัชกาลที่ ๗)	Phrabat Somdet Phra Poramenthra Maha Prajadhipok Phra Pokklao Chao Yu Hua พระบาทสมเด็จพระปรมินทรมหาประชาธิปก พระปกเกล้าเจ้าอยู่หัว	8 November 1893 27th child (31st son) of Rama V and 9th child of Queen Saovabha Phongsri	26 November 1925 (25 February 1926)	2 March 1935 (9 years, 96 days) (abdicated)	30 May 1941 (47 years old)	Younger brother of Rama VI Son of Rama V Last absolute monarch
The Siamese revolution of 1932 ended absolute monarchy
8		Rama VIII พระรามที่ ๘ (รัชกาลที่ ๘)	Phrabat Somdet Phra Poramenthra Maha Ananda Mahidol Phra Atthamaramathibodin พระบาทสมเด็จพระปรเมนทรมหาอานันทมหิดล พระอัฐมรามาธิบดินทร	20 September 1925 2nd child (1st son) of Mahidol Adulyadej and Princess Srinagarindra	2 March 1935 (13 August 1946; posthumous)[29]	9 June 1946 (11 years, 99 days) (20 years old)		Grandson of Rama V Nephew of Rama VII Under regency from 1935 to 1946
9		Rama IX พระรามที่ ๙ (รัชกาลที่ ๙)	Phrabat Somdet Phra Poraminthra Maha Bhumibol Adulyadej the Great Mahitalathibet Ramathibodi Chakri Naribodin Sayamintharathirat Boromanatbophit พระบาทสมเด็จพระปรมินทรมหาภูมิพลอดุลยเดช มหาราช มหิตลาธิเบศรรามาธิบดี จักรีนฤบดินทร สยามินทราธิราช บรมนาถบพิตร or Phra Phatthara the Great พระภัทรมหาราช	5 December 1927 3rd child (2nd son) of Mahidol Adulyadej and Princess Srinagarindra	9 June 1946 (5 May 1950)	13 October 2016 (70 years, 126 days) (88 years old)		Younger brother of Rama VIII Grandson of Rama V Under regency from 1946 to 1949 Longest-reigning Thai monarch and third longest-reigning monarch in history
10		Rama X พระรามที่ ๑๐ (รัชกาลที่ ๑๐)	Phrabat Somdet Phra Poramenthra Mahathibodi Sisinthara Maha Vajiralongkorn Phra Wachiraklao Chao Yu Hua พระบาทสมเด็จพระปรเมนทรรามาธิบดีศรีสินทรมหาวชิราลงกรณ พระวชิรเกล้าเจ้าอยู่หัว	28 July 1952 2nd child (only son) of Rama IX and Queen Sirikit	13 October 2016 (4 May 2019)[30]	Incumbent (8 years, 72 days) (72 years old)		Son of Rama IX

• 
  Family tree of the kings of Siam/Thailand

Name	Last holder		Next numerical order
	Image	Name
Rama		Rama X พระรามที่ ๑๐ (รัชกาลที่ ๑๐)	Rama XI
Ramathibodi		Somdet Phra Ramathibodi IV สมเด็จพระรามาธิบดีที่ ๔ (Rama I's original regnal name)	Ramathibodi V
Sanphet		Somdet Phra Sanphet X สมเด็จพระสรรเพชญ์ที่ ๑๐	Sanphet XI
Borommaracha		Somdet Phra Borommaracha III สมเด็จพระบรมราชาที่ ๓	Borommaracha IV
Borommarachathirat		Somdet Phra Borommarachathirat IV สมเด็จพระบรมราชาธิราชที่ ๔	Borommarachathirat V
Maha Thammaracha		Phra Maha Thammaracha IV พระมหาธรรมราชาที่ ๔	Maha Thammaracha V
Thammarachathirat		Somdet Phra Maha Thammarachathirat III สมเด็จพระมหาธรรมราชาธิราชที่ ๓	Thammarachathirat IV
Phetracha		Somdet Phra Phetracha สมเด็จพระเพทราชา	Phetracha II
Athittayawong		Somdet Phra Athittayawong สมเด็จพระอาทิตยวงศ์	Athittayawong II It is the case that the name Athittayawong was used twice, once as a personal name and once as a regnal name carried over from personal name. In this case, it can be said that King Athittayawong was actually Athittayawong II, and the next in line would be Atthitayawong III. Borommarachathirat IV's personal name was Atthitayawong. Hence, he could be considered Atthitayawong I.
Mahintharathirat		Somdet Phra Mahintharathirat สมเด็จพระมหินทราธิราช	Mahintharathirat II
Ratsadathirat		Somdet Phra Ratsadathirat สมเด็จพระรัษฎาธิราช	Ratsadathirat II
Chairachathirat		Somdet Phra Chairachathirat สมเด็จพระไชยราชาธิราช	Chairachathirat II
Yotfa		Somdet Phra Yotfa สมเด็จพระยอดฟ้า	Yotfa II
Worawongsathirat		Khun Worawongsathirat ขุนวรวงศาธิราช	Worawongsathirat II
Maha Chakkraphat		Somdet Phra Maha Chakkraphat สมเด็จพระมหาจักรพรรดิ	Maha Chakkraphat II
Intharachathirat		Somdet Phra Intharachathirat สมเด็จพระนครินทราธิราช	Intharachathirat II
Borommatrailokkanat		Somdet Phra Borommatrailokkanat สมเด็จพระบรมไตรโลกนาถ	Borommatrailokkanat II
Ramesuan		Somdet Phra Ramesuan สมเด็จพระราเมศวร	Ramesuan II It is the case that the name Ramesuan was used twice, once as a personal name and once as a regnal name. In this case, it can be said that King Ramesuan was actually Ramesuan I. Borommatrailokkanat's personal name was Ramesuan. Hence, he could be considered Ramesuan II.
Ramrachathirat		Somdet Phra Ramrachathirat สมเด็จพระรามราชาธิราช	Ramrachathirat II
Thong Lan		Somdet Phra Chao Thong Lan สมเด็จพระเจ้าทองลัน	Thong Lan II
Loe Thai		Phraya Loe Thai พระยาเลอไทย	Loe Thai II
Ngua Nam Thum		Phraya Ngua Nam Thum พระยางั่วนำถุม	Ngua Nam Thum II
Rammarat		Phrabat Kamonteng Ansi Rammarat พระบาทกมรเตงอัญศรีรามราช	Rammarat II
Ban Meuang		Pho Khun Ban Mueang พ่อขุนบานเมือง	Ban Mueang II
Inthrabodinthrathit		Kamonteng Ansi Inthrabodinthrathit กมรเตงอัญศรีอินทรบดินทราทิตย์	Inthrabodinthrathit II

Wikimedia Commons has media related to Monarchs of Thailand.

• Family tree of Thai monarchs
• Monarchy of Thailand
• List of rulers of Lan Na
• List of Thai royal consorts
• Rama (Kings of Thailand)
• Chakri dynasty
• Regent of Thailand
• Thailand

• Prince Chula Chakrabongse, HRH (1967). Lords of Life: A History of the Kings of Thailand. United Kingdom: Alvin Redman Limited.
• Prince Damrong Rajanubhab, Disuankumaan (2001). Our Wars With The Burmese: Thai-Burmese Conflict 1539-1767. Thailand: White Lotus Co. Ltd. ISBN 974-7534-58-4.
• Princess Maha Chakri Sirindhorn Foundation (2011). Directory of Thai kings (Thai: นามานุกรมพระมหากษัตริย์ไทย) (PDF). Thailand: www.nanmeebooks.com. ISBN 978-616-7308-25-8. Archived from the original (PDF) on 4 March 2012. Retrieved 8 January 2012.
• Royal Institute of Thailand (2002). "Chronology of the Kings of Ayutthaya". Archived from the original on 3 December 2013. Retrieved 8 January 2012.
• Wood, William A. R. (1924). History of Siam. Thailand: Chalermit Press. ISBN 1-931541-10-8.