The precedence of Thai royalty follows a system of ranks known as thanandon (), which are accompanied by royal titles.
The Sovereign There are two styles which can be used for a king in ordinary speech, depending on whether he has been crowned: Crowned kings: Phra Bat Somdet Phra Chao Yu Hua (เจ้า; ) is the style used in ordinary speech when referring to the kings of Thailand after their coronation. This style may be used in two ways: Preceding the name of the king; e.g., Phra Bat Somdet Phra Chao Yu Hua Phumiphon Adunyadet (; His Majesty King Bhumibol Adulyadej). More formally it can be split across the name, possibly with the omission (or modification) of the words "Phra Chao Yu Hua"; e.g., Phra Bat Somdet Phra Paramintara Maha Phumiphon Adunyadet () and Phra Bat Somdet Phra Paramindara Maha Prajadhipok Phra Pokklao Chao Yu Hua (). Uncrowned kings: Somdet Phra Chao Yu Hua (), normally preceding the king's name, is restricted to a king who has not yet been crowned. When crowned, he assumes the title of Phra Bat Somdet Phra Chao Yu Hua; e.g., Somdet Phra Chao Yu Hua Maha Wachiralongkon Bodinthrathepphayawarangkun (; His Majesty King Maha Vajiralongkorn Bodindradebayavarangkun).Bodinthrathepphayawarangkun (conventionally Bodindradebayavarangkun) is a temporary name that will be used prior to King Vajiralongkorn's coronation.
Consorts Traditionally, titles of royal wives depended on their birth titles and royal favour; only princesses of high birth (Chao Fa, Phra Ong Chao and Mom Chao Ying) assuming titles higher than Chao Chom. There were no clear rules about the hierarchy of titles above Chao Chom until the time of King Mongkut, and titles changed over successive reigns. The rule about commoners also seems to be evolving, and it appears that there are no more restrictions on a commoner from becoming queen. Most of the titles below are from King Vajiravudh's 1924 enactment of the Succession Law.
Consorts Rank Title Style Remarks Somdet Phra Akkhara Mahesi สมเด็จพระอัครมเหสี (Queen Consort) Somdet Phra Boromma Rajininatสมเด็จพระบรมราชินีนาถ(Queen Regent) Somdet Phra Nang Chao + Name + Phra Boromma Rajini Nat Her Majesty, the Queen Nat (นาถ) means "shelter", bestowed upon a Queen who has acted as regent for her husband. Somdet Phra Boromma Rajiniสมเด็จพระบรมราชินี Somdet Phra Nang Chao + Name + Phra Boromma Rajini Her Majesty, the Queen Somdet Phra Boromma Rajadeviสมเด็จพระบรมราชเทวี Somdet Phra Nang Chao + Name + Phra Boromma Rajadevi Her Majesty, the Queen Somdet Phra Akkhara Rajadeviสมเด็จพระอัครราชเทวี Somdet Phra Nang Chao + Name + Phra Akkhara Rajadevi Her Majesty, the Queen Somdet Phra Rajiniสมเด็จพระราชินีSomdet Phra Rajini + Name Temporary title before coronation Phra Mahesi พระมเหสี(Princess Consort) Phra Vara RajadeviพระวรราชเทวีPhra Nang Chao + Name + Phra Vara Rajadevi Her Royal Highness, Princess, Royal Consort Phra RajadeviพระราชเทวีPhra Nang Chao + Name + Phra Rajadevi Her Royal Highness, Princess, Royal Consort Phra Nang ThoeพระนางเธอPhra Nang Thoe + Name Her Royal Highness, Princess, Royal Consort Phra Akkhara Chaya ThoeพระอรรคชายาเธอPhra Akkhara Chaya Thoe + Name Her Highness, Princess, Royal Consort Phra Vara Raja Chaya ThoeพระวรราชชายาเธอPhra Vara Raja Chaya Thoe + Name Her Highness, Princess, Royal Consort Phra Raja Chaya ThoeพระราชชายาเธอPhra Raja Chaya Thoe + Name Her Highness, Princess, Royal Consort Phra Sanomพระสนม (Concubine) Chao Khun Phraเจ้าคุณพระ Royal Noble Chao Khun Phra + Name Appointed to During pregnancy, known as Chao Chom Manda, Manda means "mother"Phra was used during Rama VI's reign Chao Khun Chom Mandaเจ้าคุณจอมมารดา Noble concubine Chao Khun Chom Manda + Name Chao Chom Mandaเจ้าจอมมารดา Noble concubineChao Chom Manda + Name Chom Mandaจอมมารดา Front Palace Chom Manda + Name Chao Chomเจ้าจอม ConcubineChao Chom + Name Phraพระ Lady Phra + Name
Princes and princesses Holders of these titles are still considered royal, since they are (at most) two generations removed from a king. Nai Luang (ในหลวง) is an epithet for a king. Children of a king are called Luk Luang (ลูก หลวง "royal children"), and grandchildren of a king are called Laan Luang (หลาน "royal grandchildren"). The concept is similar to the French system of "princes of the blood" and the Iberian system of "infantes." In English, they are normally called "prince" or "princess". Special forms are used when one wishes to address them, although the language is less elaborate than when speaking to the king or the queen. A male Luk Luang who does not accede to the throne would assume a new royal surname, normally reflecting his birth name (as opposed to an honorific given later). The surname can be used by his wife if she is a commoner by birth, possibly with Na Ayudhya added if she has no noble title. It is otherwise not normally used until his children (or grandchildren) first hold the title of Mom Chao, when the surname will first appear in their names.
Sovereign's children
Rank Title Remarks Thai English Somdet Chao Fa Somdet Phra Anujadhiraj / Somdet Phra Kanitthadhiraj His Royal Highness, The Hereditary Prince / Her Royal Highness, The Hereditary Princess Elevated to "Heir Apparent" by Rama VI Higher than the other royal family; for example, Chakrabongse Bhuvanath, Prince of Phitsanulok Asdang Dejavudh, Prince of Nakhon Ratchasima Elevated for "Princess Royal" by Rama X Higher than the other royal family; for example, Sirindhorn, the Princess Debaratana Rajasuda, the Princess Royal Somdet Chao Fa Special Class His Royal Highness, Prince Elevated to "Special Class" by Rama VII and Bhanurangsi Savangvongse, Prince Banubandhu Vongsevoradej Somdet Phra Chao Borommawong Thoe Chao Fa First Class His Royal Highness, Prince (Princess) For a sovereign's children with: The Queen Royal consorts who are a sovereign's daughterSomdet Phra Chao Borommawong Thoe Chao Fa Second Class His Royal Highness, Prince (Princess) For a sovereign's children with: Royal consorts who are a sovereign's granddaughter A foreign princess Phra Ong Chao Special ClassSomdet Phra Chao Borommawong Thoe Phra Ong Chao His Royal Highness, Prince (Princess) For a sovereign's children with: HSH Princess A royal concubine Phra Ong Chao First Class Phra Chao Baromwongse Thoe Phra Ong Chao His Royal Highness, Prince (Princess) For a sovereign's children with: HSH Princess A royal concubine
Viceroy's children Rank Title Remarks Thai English Special Class Phra Chao Rajvorawongse Ther Chao Fa (พระเจ้าราชวรวงศ์เธอ เจ้าฟ้า) His Royal Highness, Prince (Princess) For Viceroy's children with a royal consort who is a princess Phra Ong Chao Phra Chao Rajvorawongse Ther Phra Ong Chao (พระเจ้าราชวรวงศ์เธอ พระองค์เจ้า) His Royal Highness, Prince (Princess) For children of Viceroys
Maha Sura Singhanat Maha Senanurak Maha Sakdi Balasebya Pinklao Phra Rajvorawongse Ther Phra Ong Chao (พระราชวรวงศ์เธอ พระองค์เจ้า) His Royal Highness, Prince (Princess) For children of Wichaichan
Sovereign's grandchildren Rank Title Remarks Thai English Somdet Chao Fa Somdet Phra Chao Lanh Ther Chao Fa (สมเด็จพระเจ้าหลานเธอ เจ้าฟ้า) His Royal Highness, Prince (Princess) For children of the sovereign's daughters or the sovereign's sisters with a prince. They are the third class of Chao Fa. Phra Ong Chao Phra Chao Lanh Ther Phra Ong Chao (พระเจ้าหลานเธอ พระองค์เจ้า) His Royal Highness, Prince (Princess) For children of the sovereign's sons (First Class) with a princess or royal consort. After their grandfather's reign, their title changes to Phra Chao Voravongse Ther Phra Ong Chao (พระเจ้าวรวงศ์เธอ พระองค์เจ้า) Phra Lanh Ther Phra Ong Chao (พระหลานเธอ พระองค์เจ้า) His Highness, Prince (Princess) For children of: The sovereign's sons (First Class) with a commoner elevated by the king The sovereign's sons (Second Class) with a princess After their grandfather's reign, their title changes to Phra Voravongse Ther Phra Ong Chao (พระวรวงศ์เธอ พระองค์เจ้า)Phra Sambandhawongse Ther Phra Ong Chao (พระสัมพันธวงศ์เธอ พระองค์เจ้า) His Highness, Prince (Princess) For children of Prince Matayabitaksa, maternal grandfather of Rama VMom Chao Mom Chao (หม่อมเจ้า) His Serene Highness, Prince (Princess) For children of the sovereign's sons with a commoner
Sovereign's nephew or niece Rank Title Remarks Thai EnglishSomdet Chao FaSomdet Phra Sambhandhawongse Ther Chao Fa (สมเด็จพระสัมพันธวงศ์เธอ เจ้าฟ้า) His Royal Highness, Prince (Princess) For children of Rama I's eldest sisters; Princess Debsudavadi and Princess Sri Sudaraksha Phra Ong Chao Phra Prabhandhawongse Ther Phra Ong Chao (พระประพันธวงศ์เธอ พระองค์เจ้า) His Highness, Prince (Princess) For children of deputy viceroy Anuraksha Deveshra with a royal consort Mom Chao Mom Chao (หม่อมเจ้า) His Serene Highness, Prince (Princess) For children of: Sons and daughters of Princess Debsudavadi and Princess Sri Sudaraksha's son Sons and daughters of deputy viceroy Anuraksha Deveshra with a concubine
Viceroy's grandchildren Rank Title Remarks Thai English Phra Ong ChaoPhra Wongse Ther Phra Ong Chao (พระวงศ์เธอ พระองค์เจ้า) His Highness, Prince (Princess) For the Viceroy's grandchildren who are promoted to this rank.Mom Chao Mom Chao (หม่อมเจ้า) His Serene Highness, Prince (Princess) For the Viceroy's grandchildren
Sovereign's great-grandchildren Rank Title Remarks Thai EnglishMom Chao Mom Chao (หม่อมเจ้า) His Serene Highness, Prince (Princess) For children of the sovereign's grandchildren in the class of Phra Chao Lanh Thor Phra Ong Chao (HRH, Prince)Mom Rajawongse Mom Rajawongse (หม่อมราชวงศ์) His Excellency/ His Grace For children of the sovereign's grandchildren in the class of Phra Lanh Thor Phra Ong Chao (HH Prince) and Mom Chao (HSH Prince). They are not members of the royal family.
Royal descendants More distant royal progeny, starting from the children of male Mom Chao, are considered commoners. However, these commoners have titles indicating that their ancestry can be traced back to a king.
Mom Rajawongse
Mom Rajawongse (หม่อมราชวงศ์, ; abbreviated in Thai as ม.ร.ว. and in English as M.R. and translated as "His/Her Excellency") is the title assumed by children of male Mom Chao M.C.(English) M.C. After first name Informally, they may be called Khun Chai (male) or Khun Ying (female) (). Holders of this title are occasionally erroneously referred to as princes or princesses in older English documents; it is now more common to use the correct title, "Mom Rajawongse". If a specific title is appended, sometimes the titular may be called His/Her Grace by proclamation of the King or a Prince-Regent, but not by a Queen-regent or any royal member sitting in the King's capacity as a Councillor-of-State.
Mom Luang Mom Luang (หม่อมหลวง, abbreviated in Thai ม.ล. and sometimes in English as M. L. and translated as "The Honourable") are the last royal descendants retaining a title. Mom Luang titles are conferred on children of male Mom Rajawongse. Colloquially (although incorrectly), they are sometimes addressed as "Mom"; the correct informal address is "Khun" ().
Na Ayudhya
In the Family Name Act, B. E. 2465, Rama VI ordered that royal descendants who do not hold any title should append "na Ayudhya" (ณ อยุธยา) to their surname to signify they are descended from a royal bloodline. Sometime spelled "Na Ayutthaya".
Wife of prince Wives of princes have titles, depending on the titles on both sides.
Phra Vorachaya Phra Vorachaya () is a title of the royal consort of the Crown Prince. She is elevated to Phra Chao Vorawongse Ther Phra Ong Chao.
Phra Chaya Phra Chaya () is a princess, Chao Fa (HRH Princess) or Phra Ong Chao (HRH Princess , HH Princess) who is married to prince, at every level. She retains her own title. When referring to her as a wife of the prince, she may be called "Phra Chaya Nai (husband's name)".
Chaya